summaryrefslogtreecommitdiff
path: root/docs/draft-coar-cgi-v11-03-clean.html
blob: 37835500c6338427e3e555bb1c59959c7253eb05 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
 "http://www.w3.org/TR/REC-html40/loose.dtd">
<HTML>
 <HEAD>
  <TITLE>Common Gateway Interface - 1.1 *Draft 03* [http://cgi-spec.golux.com/draft-coar-cgi-v11-03-clean.html]
  </TITLE>
<!--#if expr="$HTTP_USER_AGENT != /Lynx/" -->
 <!--#set var="GUI" value="1" -->
<!--#endif -->
  <LINK HREF="mailto:Ken.Coar@Golux.Com" rev="revised">
  <LINK REL="STYLESHEET" HREF="cgip-style-rfc.css" TYPE="text/css">
  <META name="latexstyle" content="rfc">
  <META name="author" content="Ken A L Coar">
  <META name="institute" content="IBM Corporation">
  <META name="date" content="25 June 1999">
  <META name="expires" content="Expires 31 December 1999">
  <META name="document" content="INTERNET-DRAFT">
  <META name="file" content="&lt;draft-coar-cgi-v11-03.txt&gt;">
  <META name="group" content="INTERNET-DRAFT">
<!--
    There are a lot of BNF fragments in this document.  To make it work
    in all possible browsers (including Lynx, which is used to turn it
    into text/plain), we handle these by using PREformatted blocks with
    a universal internal margin of 2, inside one-level DL blocks.
 -->
 </HEAD>
 <BODY>
  <!--
    HTML doesn't do paper pagination, so we need to fake it out.  Basing
    our formatting upon RFC2068, there are four (4) lines of header and
    four (4) lines of footer for each page.

<DIV ALIGN="CENTER">
 <PRE>




Coar, et al.               CGI/1.1 Specification                     May, 1998
INTERNET-DRAFT             Expires 1 December 1998                    [Page 2]


 </PRE>
</DIV>
  -->
  <!--
    The following weirdness wrt non-breaking spaces is to get Lynx
    (which is barely TABLE-aware) to line the left/right justified
    text up properly.
  -->
  <DIV ALIGN="CENTER">
   <TABLE WIDTH="100%" CELLPADDING=0 CELLSPACING=0>
    <TR VALIGN="TOP">
     <TD ALIGN="LEFT">
      INTERNET-DRAFT&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
     </TD>
     <TD ALIGN="RIGHT">
      &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Ken A L Coar
     </TD>
    </TR>
    <TR VALIGN="TOP">
     <TD ALIGN="LEFT">
      draft-coar-cgi-v11-03.{html,txt}&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
     </TD>
     <TD ALIGN="RIGHT">
      &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;IBM Corporation
     </TD>
    </TR>
    <TR VALIGN="TOP">
     <TD ALIGN="LEFT">
      &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
     </TD>
     <TD ALIGN="RIGHT">
      &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;D.R.T. Robinson
     </TD>
    </TR>
    <TR VALIGN="TOP">
     <TD ALIGN="LEFT">
      &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
     </TD>
     <TD ALIGN="RIGHT">
      &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E*TRADE&nbsp;UK&nbsp;Ltd.
     </TD>
    </TR>
    <TR VALIGN="TOP">
     <TD ALIGN="LEFT">
      &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
     </TD>
     <TD ALIGN="RIGHT">
      &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;25 June 1999
     </TD>
    </TR>
   </TABLE>
  </DIV>

  <H1 ALIGN="CENTER">
   The WWW Common Gateway Interface
   <BR>
   Version 1.1
  </H1>

<!--#include virtual="I-D-statement" -->

  <H2>
   <A NAME="Abstract">
    Abstract
   </A>
  </H2>
  <P>
  The Common Gateway Interface (CGI) is a simple interface for running
  external programs, software or gateways under an information server
  in a platform-independent manner. Currently, the supported information
  servers are HTTP servers.
  </P>
  <P>
  The interface has been in use by the World-Wide Web since 1993. This
  specification defines the
  "current practice" parameters of the
  'CGI/1.1' interface developed and documented at the U.S. National
  Centre for Supercomputing Applications [NCSA-CGI].
  This document also defines the use of the CGI/1.1 interface
  on the Unix and AmigaDOS(tm) systems.
  </P>
  <P>
  Discussion of this draft occurs on the CGI-WG mailing list; see the
  project Web page at 
  <SAMP>&lt;URL:<A HREF="http://CGI-Spec.Golux.Com/"
                >http://CGI-Spec.Golux.Com/</A>&gt;</SAMP>
  for details on the mailing list and the status of the project.
  </P>

<!--#if expr="$GUI" -->
  <H2>
   Revision History
  </H2>
  <P>
  The revision history of this draft is being maintained using Web-based
  GUI notation, such as struck-through characters and colour-coded
  sections.  The following legend describes how to determine the origin
  of a particular revision according to the colour of the text:
  </P>
  <DL COMPACT>
   <DT>Black
   </DT>
   <DD>Revision 00, released 28 May 1998
   </DD>
   <DT>Green
   </DT>
   <DD>Revision 01, released 28 December 1998
    <BR>
    Major structure change: Section 4, "Request Metadata (Meta-Variables)"
    was moved entirely under <A HREF="#7.0">Section 7</A>, "Data Input to the
    CGI Script."
    Due to the size of this change, it is noted here and the text in its
    former location does <EM>not</EM> appear as struckthrough.  This has
    caused major <A HREF="#6.0">sections 5</A> and following to decrement
    by one.  Other
    large text movements are likewise not marked up.  References to RFC
    1738 were changed to 2396 (1738's replacement).
   </DD>
   <DT>Red
   </DT>
   <DD>Revision 02, released 2 April, 1999
    <BR>
    Added text to <A HREF="#8.3">section 8.3</A> defining correct handling
    of HTTP/1.1
    requests using "chunked" Transfer-Encoding.  Labelled metavariable
    names in <A HREF="#8.0">section 8</A> with the appropriate detail section
    numbers.
    Clarified allowed usage of <SAMP>Status</SAMP> and
    <SAMP>Location</SAMP> response header fields.  Included new
    Internet-Draft language.
   </DD>
   <DT>Fuchsia
   </DT>
   <DD>Revision 03, released 25 June 1999
    <BR>
    Changed references from "HTTP" to "Protocol-Specific" for the listing of
    things like HTTP_ACCEPT.  Changed 'entity-body' and 'content-body' to
    'message-body.'  Added a note that response headers must comply with
    requirements of the protocol level in use.  Added a lot of stuff about
    security (section 11).  Clarified a bunch of productions.  Pointed out
    that zero-length and omitted values are indistinguishable in this
    specification.  Clarified production describing order of fields in
    script response header.  Clarified issues surrounding encoding of
    data.  Acknowledged additional contributors, and changed one of
    the authors' addresses.
   </DD>
  </DL>
<!--#endif -->

  <H2>
   <A NAME="Contents">
    Table of Contents
   </A>
  </H2>
  <DIV ALIGN="CENTER">
   <PRE>
  1 Introduction..............................................<A
                                                               HREF="#1.0"
                                                              >TBD</A>
   1.1 Purpose................................................<A
                                                               HREF="#1.1"
                                                              >TBD</A>
   1.2 Requirements...........................................<A
                                                               HREF="#1.2"
                                                              >TBD</A>
   1.3 Specifications.........................................<A
                                                               HREF="#1.3"
                                                              >TBD</A>
   1.4 Terminology............................................<A
                                                               HREF="#1.4"
                                                              >TBD</A>
  2 Notational Conventions and Generic Grammar................<A
                                                               HREF="#2.0"
                                                              >TBD</A>
   2.1 Augmented BNF..........................................<A
                                                               HREF="#2.1"
                                                              >TBD</A>
   2.2 Basic Rules............................................<A
                                                               HREF="#2.2"
                                                              >TBD</A>
  3 Protocol Parameters.......................................<A
                                                               HREF="#3.0"
                                                              >TBD</A>
   3.1 URL Encoding...........................................<A
                                                               HREF="#3.1"
                                                              >TBD</A>
   3.2 The Script-URI.........................................<A
                                                               HREF="#3.2"
                                                              >TBD</A>
  4 Invoking the Script.......................................<A
                                                               HREF="#4.0"
                                                              >TBD</A>
  5 The CGI Script Command Line...............................<A
                                                               HREF="#5.0"
                                                              >TBD</A>
  6 Data Input to the CGI Script..............................<A
                                                               HREF="#6.0"
                                                              >TBD</A>
   6.1 Request Metadata (Metavariables).......................<A
                                                               HREF="#6.1"
                                                              >TBD</A>
    6.1.1 AUTH_TYPE...........................................<A
                                                               HREF="#6.1.1"
                                                              >TBD</A>
    6.1.2 CONTENT_LENGTH......................................<A
                                                               HREF="#6.1.2"
                                                              >TBD</A>
    6.1.3 CONTENT_TYPE........................................<A
                                                               HREF="#6.1.3"
                                                              >TBD</A>
    6.1.4 GATEWAY_INTERFACE...................................<A
                                                               HREF="#6.1.4"
                                                              >TBD</A>
    6.1.5 Protocol-Specific Metavariables.....................<A
                                                               HREF="#6.1.5"
                                                              >TBD</A>
    6.1.6 PATH_INFO...........................................<A
                                                               HREF="#6.1.6"
                                                              >TBD</A>
    6.1.7 PATH_TRANSLATED.....................................<A
                                                               HREF="#6.1.7"
                                                              >TBD</A>
    6.1.8 QUERY_STRING........................................<A
                                                               HREF="#6.1.8"
                                                              >TBD</A>
    6.1.9 REMOTE_ADDR.........................................<A
                                                               HREF="#6.1.9"
                                                              >TBD</A>
    6.1.10 REMOTE_HOST........................................<A
                                                               HREF="#6.1.10"
                                                              >TBD</A>
    6.1.11 REMOTE_IDENT.......................................<A
                                                               HREF="#6.1.11"
                                                              >TBD</A>
    6.1.12 REMOTE_USER........................................<A
                                                               HREF="#6.1.12"
                                                              >TBD</A>
    6.1.13 REQUEST_METHOD.....................................<A
                                                               HREF="#6.1.13"
                                                              >TBD</A>
    6.1.14 SCRIPT_NAME........................................<A
                                                               HREF="#6.1.14"
                                                              >TBD</A>
    6.1.15 SERVER_NAME........................................<A
                                                               HREF="#6.1.15"
                                                              >TBD</A>
    6.1.16 SERVER_PORT........................................<A
                                                               HREF="#6.1.16"
                                                              >TBD</A>
    6.1.17 SERVER_PROTOCOL....................................<A
                                                               HREF="#6.1.17"
                                                              >TBD</A>
    6.1.18 SERVER_SOFTWARE....................................<A
                                                               HREF="#6.1.18"
                                                              >TBD</A>
    6.2 Request Message-Bodies................................<A
                                                               HREF="#6.2"
                                                              >TBD</A>
  7 Data Output from the CGI Script...........................<A
                                                               HREF="#7.0"
                                                              >TBD</A>
   7.1 Non-Parsed Header Output...............................<A
                                                               HREF="#7.1"
                                                              >TBD</A>
   7.2 Parsed Header Output...................................<A
                                                               HREF="#7.2"
                                                              >TBD</A>
    7.2.1 CGI header fields...................................<A
                                                               HREF="#7.2.1"
                                                              >TBD</A>
     7.2.1.1 Content-Type.....................................<A
                                                               HREF="#7.2.1.1"
                                                              >TBD</A>
     7.2.1.2 Location.........................................<A
                                                               HREF="#7.2.1.2"
                                                              >TBD</A>
     7.2.1.3 Status...........................................<A
                                                               HREF="#7.2.1.3"
                                                              >TBD</A>
     7.2.1.4 Extension header fields..........................<A
                                                               HREF="#7.2.1.3"
                                                              >TBD</A>
    7.2.2 HTTP header fields..................................<A
                                                               HREF="#7.2.2"
                                                              >TBD</A>
  8 Server Implementation.....................................<A
                                                               HREF="#8.0"
                                                              >TBD</A>
   8.1 Requirements for Servers...............................<A
                                                               HREF="#8.1"
                                                              >TBD</A>
    8.1.1 Script-URI..........................................<A
                                                               HREF="#8.1"
                                                              >TBD</A>
    8.1.2 Request Message-body Handling.......................<A
                                                               HREF="#8.1.2"
                                                              >TBD</A>
    8.1.3 Required Metavariables..............................<A
                                                               HREF="#8.1.3"
                                                              >TBD</A>
    8.1.4 Response Compliance.................................<A
                                                               HREF="#8.1.4"
                                                              >TBD</A>
   8.2 Recommendations for Servers............................<A
                                                               HREF="#8.2"
                                                              >TBD</A>
   8.3 Summary of Metavariables...............................<A
                                                               HREF="#8.3"
                                                              >TBD</A>
  9 Script Implementation.....................................<A
                                                               HREF="#9.0"
                                                              >TBD</A>
   9.1 Requirements for Scripts...............................<A
                                                               HREF="#9.1"
                                                              >TBD</A>
   9.2 Recommendations for Scripts............................<A
                                                               HREF="#9.2"
                                                              >TBD</A>
  10 System Specifications....................................<A
                                                               HREF="#10.0"
                                                              >TBD</A>
   10.1 AmigaDOS..............................................<A
                                                               HREF="#10.1"
                                                              >TBD</A>
   10.2 Unix..................................................<A
                                                               HREF="#10.2"
                                                              >TBD</A>
  11 Security Considerations..................................<A
                                                               HREF="#11.0"
                                                              >TBD</A>
   11.1 Safe Methods..........................................<A
                                                               HREF="#11.1"
                                                              >TBD</A>
   11.2 HTTP Header Fields Containing Sensitive Information...<A
                                                               HREF="#11.2"
                                                              >TBD</A>
   11.3 Script Interference with the Server...................<A
                                                               HREF="#11.3"
                                                              >TBD</A>
   11.4 Data Length and Buffering Considerations..............<A
                                                               HREF="#11.4"
                                                              >TBD</A>
   11.5 Stateless Processing..................................<A
                                                               HREF="#11.5"
                                                              >TBD</A>
  12 Acknowledgments..........................................<A
                                                               HREF="#12.0"
                                                              >TBD</A>
  13 References...............................................<A
                                                               HREF="#13.0"
                                                              >TBD</A>
  14 Authors' Addresses.......................................<A
                                                               HREF="#14.0"
                                                              >TBD</A>
     </PRE>
  </DIV>

  <H2>
   <A NAME="1.0">
    1. Introduction
   </A>
  </H2>

  <H3>
   <A NAME="1.1">
    1.1. Purpose
   </A>
  </H3>
  <P>
  Together the HTTP [<A HREF="#[3]">3</A>,<A HREF="#[8]">8</A>] server
  and the CGI script are responsible 
  for servicing a client
  request by sending back responses. The client
  request comprises a Universal Resource Identifier (URI)
  [<A HREF="#[1]">1</A>], a 
  request method, and various ancillary
  information about the request
  provided by the transport mechanism.
  </P>
  <P>
  The CGI defines the abstract parameters, known as 
  metavariables,
  which describe the client's
  request. Together with a
  concrete programmer interface this specifies a platform-independent
  interface between the script and the HTTP server.
  </P>

  <H3>
   <A NAME="1.2">
    1.2. Requirements
   </A>
  </H3>
  <P>
  This specification uses the same words as RFC 1123
  [<A HREF="#[5]">5</A>] to define the 
  significance of each particular requirement. These are:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <DL>
   <DT><EM>MUST</EM>
   </DT>
   <DD>
    <P>
    This word or the adjective 'required' means that the item is an
    absolute requirement of the specification.
    </P>
   </DD>
   <DT><EM>SHOULD</EM>
   </DT>
   <DD>
    <P>
    This word or the adjective 'recommended' means that there may
    exist valid reasons in particular circumstances to ignore this
    item, but the full implications should be understood and the case
    carefully weighed before choosing a different course.
    </P>
   </DD>
   <DT><EM>MAY</EM>
   </DT>
   <DD>
    <P>
    This word or the adjective 'optional' means that this item is
    truly optional. One vendor may choose to include the item because
    a particular marketplace requires it or because it enhances the
    product, for example; another vendor may omit the same item.
    </P>
   </DD>
  </DL>
  <P>
  An implementation is not compliant if it fails to satisfy one or more
  of the 'must' requirements for the protocols it implements. An
  implementation that satisfies all of the 'must' and all of the
  'should' requirements for its features is said to be 'unconditionally
  compliant'; one that satisfies all of the 'must' requirements but not
  all of the 'should' requirements for its features is said to be
  'conditionally compliant.'
  </P>
  
  <H3>
   <A NAME="1.3">
    1.3. Specifications
   </A>
  </H3>
  <P>
  Not all of the functions and features of the CGI are defined in the
  main part of this specification. The following phrases are used to
  describe the features which are not specified:
  </P>
  <DL>
   <DT><EM>system defined</EM>
   </DT>
   <DD>
    <P>
    The feature may differ between systems, but must be the same for
    different implementations using the same system. A system will
    usually identify a class of operating-systems. Some systems are
    defined in
    <A HREF="#10.0"
    >section 10</A> of this document.
    New systems may be defined
    by new specifications without revision of this document.
    </P>
   </DD>
   <DT><EM>implementation defined</EM>
   </DT>
   <DD>
    <P>
    The behaviour of the feature may vary from implementation to
    implementation, but a particular implementation must document its
    behaviour.
    </P>
   </DD>
  </DL>
  
  <H3>
   <A NAME="1.4">
    1.4. Terminology
   </A>
  </H3>
  <P>
  This specification uses many terms defined in the HTTP/1.1
  specification [<A HREF="#[8]">8</A>]; however, the following terms are
  used here in a 
  sense which may not accord with their definitions in that document,
  or with their common meaning.
  </P>
  
  <DL>
   <DT><EM>metavariable</EM>
   </DT>
   <DD>
    <P>
    A named parameter that carries information from the server to the
    script. It is not necessarily a variable in the operating-system's
    environment, although that is the most common implementation.
    </P>
   </DD>
  
   <DT><EM>script</EM>
   </DT>
   <DD>
    <P>
    The software which is invoked by the server <EM>via</EM> this
    interface. It 
    need not be a standalone program, but could be a
    dynamically-loaded or shared library, or even a subroutine in the
    server.  It <EM>may</EM> be a set of statements
    interpreted at run-time, as the term 'script' is frequently
    understood, but that is not a requirement and within the context
    of this specification the term has the broader definition stated.
    </P>
   </DD>
   <DT><EM>server</EM>
   </DT>
   <DD>
    <P>
    The application program which invokes the script in order to service
    requests.
    </P>
   </DD>
  </DL>
  
  <H2>
   <A NAME="2.0">
    2. Notational Conventions and Generic Grammar
   </A>
  </H2>

  <H3>
   <A NAME="2.1">
    2.1. Augmented BNF
   </A>
  </H3>
  <P>
  All of the mechanisms specified in this document are described in
  both prose and an augmented Backus-Naur Form (BNF) similar to that
  used by RFC 822 [<A HREF="#[6]">6</A>]. This augmented BNF contains
  the following constructs:
  </P>
  <DL>
   <DT>name = definition
   </DT>
   <DD>
    <P>
    The
    definition by the equal character ("="). Whitespace is only
    significant in that continuation lines of a definition are
    indented.
    </P>
   </DD>
   <DT>"literal"
   </DT>
   <DD>
    <P>
    Quotation marks (") surround literal text, except for a literal
    quotation mark, which is surrounded by angle-brackets ("&lt;" and "&gt;").
    Unless stated otherwise, the text is case-sensitive.
    </P>
   </DD>
   <DT>rule1 | rule2
   </DT>
   <DD>
    <P>
    Alternative rules are separated by a vertical bar ("|").
    </P>
   </DD>
   <DT>(rule1 rule2 rule3)
   </DT>
   <DD>
    <P>
    Elements enclosed in parentheses are treated as a single element.
    </P>
   </DD>
   <DT>*rule
   </DT>
   <DD>
    <P>
    A rule preceded by an asterisk ("*") may have zero or more
    occurrences. A rule preceded by an integer followed by an asterisk
    must occur at least the specified number of times.
    </P>
   </DD>
   <DT>[rule]
   </DT>
   <DD>
    <P>
    An element enclosed in square
    brackets ("[" and "]") is optional.
    </P>
   </DD>
  </DL>
  
  <H3>
   <A NAME="2.2">
    2.2. Basic Rules
   </A>
  </H3>
  <P>
  The following rules are used throughout this specification to
  describe basic parsing constructs.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    alpha         = lowalpha | hialpha
    alphanum      = alpha | digit
    lowalpha      = "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h"
                    | "i" | "j" | "k" | "l" | "m" | "n" | "o" | "p"
                    | "q" | "r" | "s" | "t" | "u" | "v" | "w" | "x"
                    | "y" | "z"
    hialpha       = "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H"
                    | "I" | "J" | "K" | "L" | "M" | "N" | "O" | "P"
                    | "Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X"
                    | "Y" | "Z"
    digit         = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7"
                    | "8" | "9"
    hex           = digit | "A" | "B" | "C" | "D" | "E" | "F" | "a"
                    | "b" | "c" | "d" | "e" | "f"
    escaped       = "%" hex hex
    OCTET         = &lt;any 8-bit sequence of data&gt;
    CHAR          = &lt;any US-ASCII character (octets 0 - 127)&gt;
    CTL           = &lt;any US-ASCII control character
                    (octets 0 - 31) and DEL (127)&gt;
    CR            = &lt;US-ASCII CR, carriage return (13)&gt;
    LF            = &lt;US-ASCII LF, linefeed (10)&gt;
    SP            = &lt;US-ASCII SP, space (32)&gt;
    HT            = &lt;US-ASCII HT, horizontal tab (9)&gt;
    NL            = CR | LF
    LWSP          = SP | HT | NL
    tspecial      = "(" | ")" | "@" | "," | ";" | ":" | "\" | &lt;"&gt;
                    | "/" | "[" | "]" | "?" | "&lt;" | "&gt;" | "{" | "}"
                    | SP | HT | NL
    token         = 1*&lt;any CHAR except CTLs or tspecials&gt;
    quoted-string = ( &lt;"&gt; *qdtext &lt;"&gt; ) | ( "&lt;" *qatext "&gt;")
    qdtext        = &lt;any CHAR except &lt;"&gt; and CTLs but including LWSP&gt;
    qatext        = &lt;any CHAR except "&lt;", "&gt;" and CTLs but
                    including LWSP&gt;
    mark          = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
    unreserved    = alphanum | mark
    reserved      = ";" | "/" | "?" | ":" | "@" | "&amp;" | "=" |
                    "$" | ","
    uric          = reserved | unreserved | escaped
  </PRE>
  <P>
  Note that newline (NL) need not be a single character, but can be a
  character sequence.
  </P>
  
  <H2>
   <A NAME="3.0">
    3. Protocol Parameters
   </A>
  </H2>

  <H3>
   <A NAME="3.1">
    3.1. URL Encoding
   </A>
  </H3>
  <P>
  Some variables and constructs used here are described as being
  'URL-encoded'. This encoding is described in section
  2 of RFC
  2396
  [<A HREF="#[4]">4</A>].
  </P>
  <P>
  An alternate "shortcut" encoding for representing the space
  character exists and is in common use.  Scripts MUST be prepared to
  recognise both '+' and '%20' as an encoded space in a
  URL-encoded value.
  </P>
  <P>
  Note that some unsafe characters may have different semantics if
  they are encoded. The definition of which characters are unsafe
  depends on the context.
  For example, the following two URLs do not
  necessarily refer to the same resource:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    http://somehost.com/somedir%2Fvalue
    http://somehost.com/somedir/value
  </PRE>
  <P>
  See section
  2 of RFC
  2396 [<A HREF="#[4]">4</A>]
  for authoritative treatment of this issue.
  </P>
  
  <H3>
   <A NAME="3.2">
    3.2. The Script-URI
   </A>
  </H3>
  <P>
  The 'Script-URI' is defined as the URI of the resource identified
  by the metavariables.   Often,
  this URI will be the same as 
  the URI requested by the client (the 'Client-URI'); however, it need
  not be. Instead, it could be a URI invented by the server, and so it
  can only be used in the context of the server and its CGI interface.
  </P>
  <P>
  The Script-URI has the syntax of generic-RL as defined in section 2.1
  of RFC 1808 [<A HREF="#[7]">7</A>], with the exception that object
  parameters and 
  fragment identifiers are not permitted:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    &lt;scheme&gt;://&lt;host&gt;&lt;port&gt;/&lt;path&gt;?&lt;query&gt;
  </PRE>
  <P>
  The various components of the
  Script-URI
  are defined by some of the
  metavariables (see
  <A HREF="#4.0">section 4</A>
  below);
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    script-uri = protocol "://" SERVER_NAME ":" SERVER_PORT enc-script
                 enc-path-info "?" QUERY_STRING
  </PRE>
  <P>
  where 'protocol' is obtained
  from SERVER_PROTOCOL, 'enc-script' is a
  URL-encoded version of SCRIPT_NAME and 'enc-path-info' is a
  URL-encoded version of PATH_INFO.  See
  <A HREF="#4.6">section 4.6</A> for more information about the PATH_INFO
  metavariable.
  </P>
  <P>
  Note that the scheme and the protocol are <EM>not</EM> identical;
  for instance, a resource accessed <EM>via</EM> an SSL mechanism
  may have a Client-URI with a scheme of "<SAMP>https</SAMP>"
  rather than "<SAMP>http</SAMP>".   CGI/1.1 provides no means
  for the script to reconstruct this, and therefore
  the Script-URI includes the base protocol used.
  </P>
  
  <H2>
   <A NAME="4.0">
    4. Invoking the Script
   </A>
  </H2>
  <P>
  The
  script is invoked in a system defined manner. Unless specified
  otherwise, the file containing the script will be invoked as an
  executable program.
  </P>
  
  <H2>
   <A NAME="5.0">
    5. The CGI Script Command Line
   </A>
  </H2>
  <P>
  Some systems support a method for supplying an array of strings to
  the CGI script. This is only used in the case of an 'indexed' query.
  This is identified by a "GET" or "HEAD" HTTP request with a URL
  query
  string not containing any unencoded "=" characters. For such a
  request, 
  servers SHOULD parse the search string
  into words, using the following rules:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    search-string = search-word *( "+" search-word )
    search-word   = 1*schar
    schar         = xunreserved | escaped | xreserved
    xunreserved   = alpha | digit | xsafe | extra
    xsafe         = "$" | "-" | "_" | "."
    xreserved     = ";" | "/" | "?" | ":" | "@" | "&"
  </PRE>
  <P>
  After parsing, each word is URL-decoded, optionally encoded in a
  system defined manner,
  and then the argument list is set to the list
  of words.
  </P>
  <P>
  If the server cannot create any part of the argument list, then the
  server SHOULD NOT generate any command line information. For example, the
  number of arguments may be greater than operating system or server
  limitations permit, or one of the words may not be representable as an
  argument.
  </P>
  <P>
  Scripts SHOULD check to see if the QUERY_STRING value contains an
  unencoded "=" character, and SHOULD NOT use the command line arguments
  if it does.
  </P>

  <H2>
   <A NAME="6.0">
    6. Data Input to the CGI Script
   </A>
  </H2>
  <P>
  Information about a request comes from two different sources: the
  request header, and any associated
  message-body.
  Servers MUST
  make portions of this information available to
   scripts.
  </P>

  <H3>
   <A NAME="6.1">
    6.1. Request Metadata
    (Metavariables)
   </A>
  </H3>
  <P>
  Each CGI server
  implementation MUST define a mechanism
  to pass data about the request from 
  the server to the script.
  The metavariables containing these
  data
  are accessed by the script in a system
  defined manner. 
  The
  representation of the characters in the
  metavariables is
  system defined.
  </P>
  <P>
  This specification does not distinguish between the representation of
  null values and missing ones.  Whether null or missing values
  (such as a query component of "?" or "", respectively) are represented
  by undefined metavariables or by metavariables with values of "" is
  implementation-defined.
  </P>
  <P>
  Case is not significant in the
  metavariable
  names, in that there cannot be two
  different variables
  whose names differ in case only. Here they are
  shown using a canonical representation of capitals plus underscore
  ("_"). The actual representation of the names is system defined; for
  a particular system the representation MAY be defined differently
  than this.
  </P>
  <P>
  Metavariable
  values MUST be
  considered case-sensitive except as noted
  otherwise.
  </P>
  <P>
  The canonical
  metavariables
  defined by this specification are:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    AUTH_TYPE
    CONTENT_LENGTH
    CONTENT_TYPE
    GATEWAY_INTERFACE
    PATH_INFO
    PATH_TRANSLATED
    QUERY_STRING
    REMOTE_ADDR
    REMOTE_HOST
    REMOTE_IDENT
    REMOTE_USER
    REQUEST_METHOD
    SCRIPT_NAME
    SERVER_NAME
    SERVER_PORT
    SERVER_PROTOCOL
    SERVER_SOFTWARE
  </PRE>
  <P>
  Metavariables with names beginning with the protocol name (<EM>e.g.</EM>,
  "HTTP_ACCEPT") are also canonical in their description of request header
  fields.  The number and meaning of these fields may change independently
  of this specification.  (See also <A HREF="#6.1.5">section 6.1.5</A>.)
  </P>

  <H4>
   <A NAME="6.1.1">
    6.1.1. AUTH_TYPE
   </A>
  </H4>
  <P>
  This variable is specific to requests made 
  <EM>via</EM> the
  "<CODE>http</CODE>"
  scheme.
  </P>
  <P>
  If the Script-URI
  required access authentication for external
  access, then the server 
  MUST set
  the value of
  this variable 
  from the '<SAMP>auth-scheme</SAMP>' token in
  the request's "<SAMP>Authorization</SAMP>" header
  field.
  Otherwise
  it is
  set to NULL.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    AUTH_TYPE   = "" | auth-scheme
    auth-scheme = "Basic" | "Digest" | token
  </PRE>
  <P>
  HTTP access authentication schemes are described in section 11 of the
  HTTP/1.1 specification [<A HREF="#[8]">8</A>]. The auth-scheme is
  not case-sensitive. 
  </P>
  <P>
  Servers
  MUST
  provide this metavariable
  to scripts if the request
  header included an "<SAMP>Authorization</SAMP>" field
  that was authenticated.
  </P>

  <H4>
   <A NAME="6.1.2">
    6.1.2. CONTENT_LENGTH
   </A>
  </H4>
  <P>
  This
  metavariable
  is set to the
  size of the message-body
  entity attached to the request, if any, in decimal
  number of octets. If no data are attached, then this
  metavariable
  is either NULL or not
  defined. The syntax is
  the same as for
  the HTTP "<SAMP>Content-Length</SAMP>" header field (section 14.14, HTTP/1.1
  specification [<A HREF="#[8]">8</A>]).
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    CONTENT_LENGTH = "" | 1*digit
  </PRE>
  <P>
  Servers MUST provide this metavariable
  to scripts if the request
  was accompanied by a
  message-body entity.
  </P>

  <H4>
   <A NAME="6.1.3">
    6.1.3. CONTENT_TYPE
   </A>
  </H4>
  <P>
  If the request includes a
  message-body,
  CONTENT_TYPE is set
  to
  the Internet Media Type
  [<A HREF="#[9]">9</A>] of the attached
  entity if the type was provided <EM>via</EM>
  a "<SAMP>Content-type</SAMP>" field in the
  request header, or if the server can determine it in the absence
  of a supplied "<SAMP>Content-type</SAMP>" field. The syntax is the 
  same as for the HTTP
  "<SAMP>Content-Type</SAMP>" header field.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    CONTENT_TYPE = "" | media-type
    media-type   = type "/" subtype *( ";" parameter)
    type         = token
    subtype      = token
    parameter    = attribute "=" value
    attribute    = token
    value        = token | quoted-string
  </PRE>
  <P>
  The type, subtype,
  and parameter attribute names are not
  case-sensitive. Parameter values MAY be case sensitive.
  Media types and their use in HTTP are described
  in section 3.7 of the
  HTTP/1.1 specification [<A HREF="#[8]">8</A>].
  </P>
  <P>
  Example:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    application/x-www-form-urlencoded
  </PRE>
  <P>
  There is no default value for this variable. If and only if it is
  unset, then the script MAY attempt to determine the media type from
  the data received. If the type remains unknown, then
  the script MAY choose to either assume a
  content-type of
  <SAMP>application/octet-stream</SAMP> 
  or reject the request with  a 415 ("Unsupported Media Type")
  error.  See <A HREF="#7.2.1.3">section 7.2.1.3</A>
  for more information about returning error status values.
  </P>
  <P>
  Servers MUST provide this metavariable
  to scripts if
  a "<SAMP>Content-Type</SAMP>" field was present
  in the original request header.  If the server receives a request
  with an attached entity but no "<SAMP>Content-Type</SAMP>"
  header field, it MAY attempt to
  determine the correct datatype, or it MAY omit this
  metavariable when
  communicating the request information to the script.
  </P>

  <H4>
   <A NAME="6.1.4">
    6.1.4. GATEWAY_INTERFACE
   </A>
  </H4>
  <P>
  This
  metavariable
  is set to
  the dialect of CGI being used
  by the server to communicate with the script.
  Syntax:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    GATEWAY_INTERFACE = "CGI" "/" major "." minor
    major             = 1*digit
    minor             = 1*digit
  </PRE>
  <P>
  Note that the major and minor numbers are treated as separate
  integers and hence each may be 
  more than a single
  digit. Thus CGI/2.4 is a lower version than CGI/2.13 which in turn
  is lower than CGI/12.3. Leading zeros in either
  the major or the minor number MUST be ignored by scripts and
  SHOULD NOT be generated by servers.
  </P>
  <P>
  This document defines the 1.1 version of the CGI interface
  ("CGI/1.1").
  </P>
  <P>
  Servers MUST provide this metavariable
  to scripts.
  </P>

  <H4>
   <A NAME="6.1.5">
    6.1.5. Protocol-Specific Metavariables
   </A>
  </H4>
  <P>
  These metavariables are specific to
  the protocol 
  <EM>via</EM> which the request is made.
  Interpretation of these variables depends on the value of 
  the 
  SERVER_PROTOCOL
  metavariable
  (see
  <A HREF="#6.1.17">section 6.1.17</A>).
  </P>
  <P>
  Metavariables
  with names beginning with "HTTP_" contain
  values from the request header, if the
  scheme used was HTTP.
  Each
  HTTP header field name is converted to upper case, has all occurrences of
  "-" replaced with "_",
  and has "HTTP_" prepended to  form
  the metavariable name.
  Similar transformations are applied for other
  protocols.
  The header data MAY be presented as sent
  by the client, or MAY be rewritten in ways which do not change its
  semantics. If multiple header fields with the same field-name are received
  then  the server
  MUST  rewrite them as though they
  had been received as a single header field having the same
  semantics before being represented in a
  metavariable.
  Similarly, a header field that is received on more than one line
  MUST be merged into a single line. The server MUST, if necessary,
  change the representation of the data (for example, the character
  set) to be appropriate for a CGI
  metavariable.
  <!-- ###NOTE: See if 2068 describes this thoroughly, and
  point there if so. -->
  </P>
  <P>
  Servers are
  not required to create
  metavariables for all
  the request
  header fields that they
  receive. In particular,
  they MAY 
  decline to make available any
  header fields carrying authentication information, such as
  "<SAMP>Authorization</SAMP>", or
  which are available to the script
  <EM>via</EM> other metavariables,
  such as "<SAMP>Content-Length</SAMP>" and "<SAMP>Content-Type</SAMP>".
  </P>

  <H4>
   <A NAME="6.1.6">
    6.1.6. PATH_INFO
   </A>
  </H4>
  <P>
  The PATH_INFO
  metavariable
  specifies
  a path to be interpreted by the CGI script. It identifies the
  resource or sub-resource to be returned
  by the CGI
  script, and it is derived from the portion
  of the URI path following the script name but preceding
  any query data.
  The syntax
  and semantics are similar to a decoded HTTP URL
  'path' token
  (defined in
  RFC 2396
  [<A HREF="#[4]">4</A>]), with the exception
  that a PATH_INFO of "/" 
  represents a single void path segment.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    PATH_INFO = "" | ( "/" path )
    path      = segment *( "/" segment )
    segment   = *pchar
    pchar     = &lt;any CHAR except "/"&gt;
  </PRE>
  <P>
  The PATH_INFO string is the trailing part of the &lt;path&gt; component of
  the Script-URI
  (see <A HREF="#3.2">section 3.2</A>)
  that follows the SCRIPT_NAME 
  portion of the path.
  </P>
  <P>
  Servers MAY impose their own restrictions and
  limitations on what values they will accept for PATH_INFO, and MAY
  reject or edit any values they
  consider objectionable before passing
  them to the script.
  </P>
  <P>
  Servers MUST make this URI component available
  to CGI scripts.  The PATH_INFO
  value is case-sensitive, and the
  server MUST preserve the case of the PATH_INFO element of the URI
  when making it available to scripts.
  </P>

  <H4>
   <A NAME="6.1.7">
    6.1.7. PATH_TRANSLATED
   </A>
  </H4>
  <P>
  PATH_TRANSLATED is derived by taking any path-info component of the
  request URI (see
  <A HREF="#6.1.6">section 6.1.6</A>), decoding it
  (see <A HREF="#3.1">section 3.1</A>), parsing it as a URI in its own
  right, and performing any virtual-to-physical
  translation appropriate to map it onto the
  server's document repository structure.
  If the request URI includes no path-info
  component, the PATH_TRANSLATED metavariable SHOULD NOT be defined.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    PATH_TRANSLATED = *CHAR
  </PRE>
  <P>
  For a request such as the following:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    http://somehost.com/cgi-bin/somescript/this%2eis%2epath%2einfo
  </PRE>
  <P>
  the PATH_INFO component would be decoded, and the result
  parsed as though it were a request for the following:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    http://somehost.com/this.is.the.path.info
  </PRE>
  <P>
  This would then be translated to a
  location in the server's document repository,
  perhaps a filesystem path something
  like this:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    /usr/local/www/htdocs/this.is.the.path.info
  </PRE>
  <P>
  The result of the translation is the value of PATH_TRANSLATED.
  </P>
  <P>
  The value of PATH_TRANSLATED may or may not map to a valid
  repository
  location.
  Servers MUST preserve the case of the path-info
  segment if and only if the underlying
  repository
  supports case-sensitive
  names.  If the
  repository
  is only case-aware, case-preserving, or case-blind
  with regard to
  document names,
  servers are not required to preserve the
  case of the original segment through the translation.
  </P>
  <P>
  The 
  translation
  algorithm the server uses to derive PATH_TRANSLATED is
  implementation defined; CGI scripts which use this variable may
  suffer limited portability.
  </P>
  <P>
  Servers SHOULD provide this metavariable
  to scripts if and only if the request URI includes a
  path-info component.
  </P>

  <H4>
   <A NAME="6.1.8">
    6.1.8. QUERY_STRING
   </A>
  </H4>
  <P>
  A URL-encoded 
  string; the &lt;query&gt; part of the
  Script-URI.
  (See
  <A HREF="#3.2">section 3.2</A>.)
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    QUERY_STRING = query-string
    query-string = *uric
  </PRE>
  <P>
  The URL syntax for a  query
  string is described in
  section 3 of
  RFC 2396
  [<A HREF="#[4]">4</A>].
  </P>
  <P>
  Servers MUST supply this value to scripts.
  The QUERY_STRING value is case-sensitive.
  If the Script-URI does not include a query component,
  the QUERY_STRING metavariable MUST be defined as an empty string ("").
  </P>

  <H4>
   <A NAME="6.1.9">
    6.1.9. REMOTE_ADDR
   </A>
  </H4>
  <P>
  The IP address of the client
  sending the request to the server. This
  is not necessarily that of the user
  agent
  (such as if the request came through a proxy).
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    REMOTE_ADDR  = hostnumber
    hostnumber   = ipv4-address | ipv6-address
  </PRE>
  <P>
  The definitions of <SAMP>ipv4-address</SAMP> and <SAMP>ipv6-address</SAMP>
  are provided in Appendix B of RFC 2373 [<A HREF="#[13]">13</A>].
  </P>
  <P>
  Servers MUST supply this value to scripts.
  </P>

  <H4>
   <A NAME="6.1.10">
    6.1.10. REMOTE_HOST
   </A>
  </H4>
  <P>
  The fully qualified domain name of the
  client sending the request to
  the server, if available, otherwise NULL.
  (See <A HREF="#6.1.9">section 6.1.9</A>.)
  Fully qualified domain names take the form as described in
  section 3.5 of RFC 1034 [<A HREF="#[10]">10</A>] and section 2.1 of
  RFC 1123 [<A HREF="#[5]">5</A>].  Domain names are not case sensitive.
  </P>
  <P>
  Servers SHOULD provide this information to
  scripts.
  </P>
  
  <H4>
   <A NAME="6.1.11">
    6.1.11. REMOTE_IDENT
   </A>
  </H4>
  <P>
  The identity information reported about the connection by a
  RFC 1413 [<A HREF="#[11]">11</A>] request to the remote agent, if
  available. Servers
  MAY choose not
  to support this feature, or not to request the data
  for efficiency reasons.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    REMOTE_IDENT = *CHAR
  </PRE>
  <P>
  The data returned
  may be used for authentication purposes, but the level
  of trust reposed in them should be minimal.
  </P>
  <P>
  Servers MAY supply this information to scripts if the
  RFC1413 [<A HREF="#[11]">11</A>] lookup is performed.
  </P>
  
  <H4>
   <A NAME="6.1.12">
    6.1.12. REMOTE_USER
   </A>
  </H4>
  <P>
  If the request required authentication using the "Basic"
  mechanism (<EM>i.e.</EM>, the AUTH_TYPE
  metavariable is set
  to "Basic"), then the value of the REMOTE_USER
  metavariable is set to the
  user-ID supplied.  In all other cases
  the value of this metavariable
  is undefined.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    REMOTE_USER = *OCTET
  </PRE>
  <P>
  This variable is specific to requests made <EM>via</EM> the
  HTTP protocol.
  </P>
  <P>
  Servers SHOULD provide this metavariable
  to scripts.
  </P>
  
  <H4>
   <A NAME="6.1.13">
    6.1.13. REQUEST_METHOD
   </A>
  </H4>
  <P>
  The REQUEST_METHOD
  metavariable
  is set to the
  method with which the request was made, as described in section
  5.1.1 of the HTTP/1.0 specification [<A HREF="#[3]">3</A>] and
  section 5.1.1 of the 
  HTTP/1.1 specification [<A HREF="#[8]">8</A>].
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    REQUEST_METHOD   = http-method
    http-method      = "GET" | "HEAD" | "POST" | "PUT" | "DELETE"
                       | "OPTIONS" | "TRACE" | extension-method
    extension-method = token
  </PRE>
  <P>
  The method is case sensitive. 
  CGI/1.1 servers MAY choose to process some methods
  directly rather than passing them to scripts.
  </P>
  <P>
  This variable is specific to requests made with HTTP.
  </P>
  <P>
  Servers MUST provide this metavariable
  to scripts.
  </P>
  
  <H4>
   <A NAME="6.1.14">
    6.1.14. SCRIPT_NAME
   </A>
  </H4>
  <P>
  The SCRIPT_NAME
  metavariable
  is
  set to a URL path that could identify the CGI script (rather than the
  script's
  output). The syntax and semantics are identical to a
  decoded HTTP URL 'path' token
  (see RFC 2396
  [<A HREF="#[4]">4</A>]).
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    SCRIPT_NAME = "" | ( "/" [ path ] )
  </PRE>
  <P>
  The SCRIPT_NAME string is some leading part of the &lt;path&gt; component
  of the Script-URI derived in some
  implementation defined manner.
  No PATH_INFO or QUERY_STRING segments
  (see sections <A HREF="#6.1.6">6.1.6</A> and
  <A HREF="#6.1.8">6.1.8</A>) are included
  in the SCRIPT_NAME value.
  </P>
  <P>
  Servers MUST provide this metavariable
  to scripts.
  </P>
  
  <H4>
   <A NAME="6.1.15">
    6.1.15. SERVER_NAME
   </A>
  </H4>
  <P>
  The SERVER_NAME
  metavariable
  is set to the
  name  of the
  server, as 
  derived from the &lt;host&gt; part of the
  Script-URI
  (see <A HREF="#3.2">section 3.2</A>).
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    SERVER_NAME = hostname | hostnumber
  </PRE>
  <P>
  Servers MUST provide this metavariable
  to scripts.
  </P>

  <H4>
   <A NAME="6.1.16">
    6.1.16. SERVER_PORT
   </A>
  </H4>
  <P>
  The SERVER_PORT
  metavariable
  is set to the
  port on which the
  request was received, as used in the &lt;port&gt;
  part of the Script-URI.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    SERVER_PORT = 1*digit
  </PRE>
  <P>
  If the &lt;port&gt; portion of the script-URI is blank, the actual
  port number upon which the request was received MUST be supplied.
  </P>
  <P>
  Servers MUST provide this metavariable
  to scripts.
  </P>
  
  <H4>
   <A NAME="6.1.17">
    6.1.17. SERVER_PROTOCOL
   </A>
  </H4>
  <P>
  The SERVER_PROTOCOL
  metavariable
  is set to
  the
  name and revision of the information protocol with which
  the
  request
  arrived.  This is not necessarily the same as the protocol version used by
  the server in its response to the client.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    SERVER_PROTOCOL   = HTTP-Version | extension-version
                        | extension-token
    HTTP-Version      = "HTTP" "/" 1*digit "." 1*digit
    extension-version = protocol "/" 1*digit "." 1*digit
    protocol          = 1*( alpha | digit | "+" | "-" | "." )
    extension-token   = token
  </PRE>
  <P>
  'protocol' is a version of the &lt;scheme&gt; part of the
  Script-URI, but is
  not identical to it.  For example, the scheme of a request may be
  "<SAMP>https</SAMP>" while the protocol remains "<SAMP>http</SAMP>".
  The protocol is not case sensitive, but
  by convention, 'protocol' is in
  upper case.
  </P>
  <P>
  A well-known extension token value is "INCLUDED",
  which signals that the current document is being included as part of
  a composite document, rather than being the direct target of the
  client request.
  </P>
  <P>
  Servers MUST provide this metavariable
  to scripts.
  </P>
  
  <H4>
   <A NAME="6.1.18">
    6.1.18. SERVER_SOFTWARE
   </A>
  </H4>
  <P>
  The SERVER_SOFTWARE
  metavariable
  is set to the
  name and version of the information server software answering the
  request (and running the gateway).
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    SERVER_SOFTWARE = 1*product
    product         = token [ "/" product-version ]
    product-version = token
  </PRE>
  <P>
  Servers MUST provide this metavariable
  to scripts.
  </P>

  <H3>
   <A NAME="6.2">
    6.2. Request Message-Bodies
   </A>
  </H3>
  <P>
  As there may be a data entity attached to the request, there MUST be
  a system defined method for the script to read
  these data. Unless
  defined otherwise, this will be <EM>via</EM> the 'standard input' file
  descriptor.
  </P>
  <P>
  If the CONTENT_LENGTH value (see <A HREF="#6.1.2">section 6.1.2</A>)
  is non-NULL, the server MUST supply at least that many bytes to
  scripts on the standard input stream.
  Scripts are
  not obliged to read the data.
  Servers MAY signal an EOF condition after CONTENT_LENGTH bytes have been
  read, but are
  not obligated to do so.  Therefore, scripts
  MUST NOT
  attempt to read more than CONTENT_LENGTH bytes, even if more data
  are available.
  </P>
  <P>
  For non-parsed header (NPH) scripts (see
  <A HREF="#7.1">section 7.1</A>
  below), 
  servers SHOULD
  attempt to ensure that the data
  supplied to the script are precisely
  as supplied by the client and unaltered by
  the server.
  </P>
  <P>
  <A HREF="#8.1.2">Section 8.1.2</A> describes the requirements of
  servers with regard to requests that include
  message-bodies.
  </P>

  <H2>
   <A NAME="7.0">
    7. Data Output from the CGI Script
   </A>
  </H2>
  <P>
  There MUST be a system defined method for the script to send data
  back to the server or client; a script MUST always return some data.
  Unless defined otherwise, this will be <EM>via</EM> the 'standard
  output' file descriptor.
  </P>
  <P>
  There are two forms of output that  scripts can supply to servers: non-parsed
  header (NPH) output, and parsed header output.
  Servers MUST support parsed header
  output and MAY support NPH output.  The method of
  distinguishing between the two
  types of output (or scripts) is implementation defined.
  </P>
  <P>
  Servers MAY implement a timeout period within which data must be
  received from scripts.  If a server implementation defines such
  a timeout and receives no data from a script within the timeout
  period, the server MAY terminate the script process and SHOULD
  abort the client request with
  either a
  '504 Gateway Timed Out' or a
  '500 Internal Server Error' response.
  </P>

  <H3>
   <A NAME="7.1">
    7.1. Non-Parsed Header Output
   </A>
  </H3>
  <P>
  Scripts using the NPH output form
  MUST return a complete HTTP response message, as described
  in Section 6 of the HTTP specifications
  [<A HREF="#[3]">3</A>,<A HREF="#[8]">8</A>].
   NPH scripts
  MUST use the SERVER_PROTOCOL variable to determine the appropriate format
  for a response.
  </P>
  <P>
  Servers
  SHOULD attempt to ensure that the script output is sent
  directly to the client, with minimal
  internal and no transport-visible
  buffering.
  </P>
  
  <H3>
   <A NAME="7.2">
    7.2. Parsed Header Output
   </A>
  </H3>
  <P>
  Scripts using the parsed header output form MUST supply
  a CGI response message to the server
  as follows:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    CGI-Response   = *optional-field CGI-Field *optional-field NL [ Message-Body ]
    optional-field = ( CGI-Field | HTTP-Field )
    CGI-Field      = Content-type
                   | Location
                   | Status
                   | extension-header
  </PRE>
  <P><!-- ##### If HTTP defines x-headers, remove ours except x-cgi- -->
  The response comprises a header and a body, separated by a blank line.
  The body may be NULL.
  The header fields are either CGI header fields to be interpreted by
  the server, or HTTP header fields
  to be included in the response returned
  to the client
  if the request method is HTTP. At least one
  CGI-Field MUST be
  supplied, but no CGI  field name may be used more than once
  in a response.
  If a body is supplied, then a "<SAMP>Content-type</SAMP>"
  header field MUST be
  supplied by the script,
  otherwise the script MUST send a "<SAMP>Location</SAMP>"
  or "<SAMP>Status</SAMP>" header field. If a
  <SAMP>Location</SAMP> CGI-Field
  is returned, then the script MUST NOT supply
  any HTTP-Fields.
  </P>
  <P>
  Each header field in a CGI-Response MUST be specified on a single line;
  CGI/1.1 does not support continuation lines.
  </P>

  <H4>
   <A NAME="7.2.1">
    7.2.1. CGI header fields
   </A>
  </H4>
  <P>
  The CGI header fields have the generic syntax:
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    generic-field  = field-name ":" [ field-value ] NL
    field-name     = token
    field-value    = *( field-content | LWSP )
    field-content  = *( token | tspecial | quoted-string )
  </PRE>
  <P>
  The field-name is not case sensitive; a NULL field value is
  equivalent to the header field not being sent.
  </P>

  <H4>
   <A NAME="7.2.1.1">
    7.2.1.1. Content-Type
   </A>
  </H4>
  <P>
  The Internet Media Type [<A HREF="#[9]">9</A>] of the entity
  body, which is to be sent unmodified to the client.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    Content-Type = "Content-Type" ":" media-type NL
  </PRE>
  <P>
  This is actually an HTTP-Field
  rather than a CGI-Field, but
  it is listed here because of its importance in the CGI dialogue as
  a member of the "one of these is required" set of header
  fields.
  </P>
  
  <H4>
   <A NAME="7.2.1.2">
    7.2.1.2. Location
   </A>
  </H4>
  <P>
  This is used to specify to the server that the script is returning a
  reference to a document rather than an actual document.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    Location         = "Location" ":"
                       ( fragment-URI | rel-URL-abs-path ) NL
    fragment-URI     = URI [ # fragmentid ]
    URI              = scheme ":" *qchar
    fragmentid       = *qchar
    rel-URL-abs-path = "/" [ hpath ] [ "?" query-string ]
    hpath            = fpsegment *( "/" psegment )
    fpsegment        = 1*hchar
    psegment         = *hchar
    hchar            = alpha | digit | safe | extra
                       | ":" | "@" | "& | "="
  </PRE>
  <P>
  The Location
  value is either an absolute URI with optional fragment,
  as defined in RFC 1630 [<A HREF="#[1]">1</A>], or an absolute path
  within the server's URI space (<EM>i.e.</EM>,
  omitting the scheme and network-related fields) and optional 
  query-string. If an absolute URI is returned by the script,
  then the
  server MUST generate a
  '302 redirect' HTTP response
  message unless the script has supplied an
  explicit Status response header field.
  Scripts returning an absolute URI MAY choose to
  provide a message-body.  Servers MUST make any appropriate modifications
  to the script's output to ensure the response to the user-agent complies
  with the response protocol version.
  If the Location value is a path, then the server
  MUST generate
  the response that it would have produced in response to a request
  containing the URL
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    scheme "://" SERVER_NAME ":" SERVER_PORT rel-URL-abs-path
  </PRE>
  <P>
  Note: If the request was accompanied by a
  message-body
  (such as for a POST request), and the script
  redirects the request with a Location field, the
  message-body
  may not be
  available to the resource that is the target of the redirect.
  </P>

  <H4>
   <A NAME="7.2.1.3">
    7.2.1.3. Status
   </A>
  </H4>
  <P>
  The "<SAMP>Status</SAMP>" header field is used to indicate to the server what
  status code the server MUST use in the response message.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    Status        = "Status" ":" digit digit digit SP reason-phrase NL
    reason-phrase = *&lt;CHAR, excluding CTLs, NL&gt;
  </PRE>
  <P>
  The valid status codes are listed in section 6.1.1 of the HTTP/1.0
  specifications [<A HREF="#[3]">3</A>]. If the SERVER_PROTOCOL is
  "HTTP/1.1", then the status codes defined in the HTTP/1.1
  specification [<A HREF="#[8]">8</A>] may 
  be used. If the script does not return a "<SAMP>Status</SAMP>" header
  field, then "200 OK" SHOULD be assumed by the server.
  </P>
  <P>
  If a script is being used to handle a particular error or condition
  encountered by the server, such as a '404 Not Found' error, the script
  SHOULD use the "<SAMP>Status</SAMP>" CGI header field to propagate the error
  condition back to the client.  <EM>E.g.</EM>, in the example mentioned it
  SHOULD include a "Status:&nbsp;404&nbsp;Not&nbsp;Found" in the
  header data returned to the server.
  </P>
  
  <H4>
   <A NAME="7.2.1.4">
    7.2.1.4. Extension header fields
   </A>
  </H4>
  <P>
  Scripts MAY include in their CGI response header additional fields
  not defined in this or the HTTP specification.
  These are called "extension" fields,
  and have the syntax of a <SAMP>generic-field</SAMP> as defined in
  <A HREF="#7.2.1">section 7.2.1</A>.  The name of an extension field
  MUST NOT conflict with a field name defined in this or any other
  specification; extension field names SHOULD begin with "X-CGI-"
  to ensure uniqueness.
  </P>

  <H4>
   <A NAME="7.2.2">
    7.2.2. HTTP header fields
   </A>
  </H4>
  <P>
  The script MAY return any other header fields defined by the
  specification
  for the SERVER_PROTOCOL (HTTP/1.0 [<A HREF="#[3]">3</A>] or HTTP/1.1
  [<A HREF="#[8]">8</A>]).
  Servers MUST resolve conflicts beteen CGI header
  and HTTP header formats or names (see <A HREF="#8.0">section 8</A>).
  </P>

  <H2>
   <A NAME="8.0">
    8. Server Implementation
   </A>
  </H2>
  <P>
  This section defines the requirements that must be met by HTTP
  servers in order to provide a coherent and correct CGI/1.1
  environment in which scripts may function.  It is intended
  primarily for server implementors, but it is useful for
  script authors to be familiar with the information as well.
  </P>

  <H3>
   <A NAME="8.1">
    8.1. Requirements for Servers
   </A>
  </H3>
  <P>
  In order to be considered CGI/1.1-compliant, a server must meet
  certain basic criteria and provide certain minimal functionality.
  The details of these requirements are described in the following sections.
  </P>

  <H3>
   <A NAME="8.1.1">
    8.1.1. Script-URI
   </A>
  </H3>
  <P>
  Servers MUST support the standard mechanism (described below) which
  allows 
  script authors to determine
  what URL to use in documents
  which reference the script;
  specifically, what URL to use in order to
  achieve particular settings of the
  metavariables. This
  mechanism is as follows:
  </P>
  <P>
  The server 
  MUST translate the header data from the CGI header field syntax to
  the HTTP
  header field syntax if these differ. For example, the character
  sequence for 
  newline (such as Unix's ASCII NL) used by CGI scripts may not be the
  same as that used by HTTP (ASCII CR followed by LF). The server MUST
  also resolve any conflicts between header fields returned by the script
  and header fields that it would otherwise send itself.
  </P>

  <H3>
   <A NAME="8.1.2">
    8.1.2. Request Message-body Handling
   </A>
  </H3>
  <P>
  These are the requirements for server handling of message-bodies directed
  to CGI/1.1 resources:
  </P>
  <OL>
   <LI>The message-body the server provides to the CGI script MUST
    have any transfer encodings removed.
   </LI>
   <LI>The server MUST derive and provide a value for the CONTENT_LENGTH
    metavariable that reflects the length of the message-body after any
    transfer decoding.
   </LI>
   <LI>The server MUST leave intact any content-encodings of the message-body.
   </LI>
  </OL>

  <H3>
   <A NAME="8.1.3">
    8.1.3. Required Metavariables
   </A>
  </H3>
  <P>
  Servers MUST provide scripts with certain information and
  metavariables
  as described in <A HREF="#8.3">section 8.3</A>.
  </P>

  <H3>
   <A NAME="8.1.4">
    8.1.4. Response Compliance
   </A>
  </H3>
  <P>
  Servers MUST ensure that responses sent to the user-agent meet all
  requirements of the protocol level in effect.  This may involve
  modifying, deleting, or augmenting any header
  fields and/or message-body supplied by the script.
  </P>

  <H3>
   <A NAME="8.2">
    8.2. Recommendations for Servers
   </A>
  </H3>
  <P>
  Servers SHOULD provide the "<SAMP>query</SAMP>" component of the script-URI
  as command-line arguments to scripts if it does not
  contain any unencoded '=' characters and the command-line arguments can
  be generated in an unambiguous manner.
  (See <A HREF="#5.0">section 5</A>.)
  </P>
  <P>
  Servers SHOULD set the AUTH_TYPE
  metavariable to the value of the
  '<SAMP>auth-scheme</SAMP>' token of the "<SAMP>Authorization</SAMP>"
  field if it was supplied as part of the request header.
  (See <A HREF="#6.1.1">section 6.1.1</A>.)
  </P>
  <P>
  Where applicable, servers SHOULD set the current working directory
  to the directory in which the script is located before invoking
  it.
  </P>
  <P>
  Servers MAY reject with error '404 Not Found'
  any requests that would result in
  an encoded "/" being decoded into PATH_INFO or SCRIPT_NAME, as this
  might represent a loss of information to the script.
  </P>
  <P>
  Although the server and the CGI script need not be consistent in
  their handling of URL paths (client URLs and the PATH_INFO data,
  respectively), server authors may wish to impose consistency.
  So the server implementation SHOULD define its behaviour for the
  following cases:
  </P>
  <OL>
   <LI>define any restrictions on allowed characters, in particular
    whether ASCII NUL is permitted;
   </LI>
   <LI>define any restrictions on allowed path segments, in particular
    whether non-terminal NULL segments are permitted;
   </LI>
   <LI>define the behaviour for <SAMP>"."</SAMP> or <SAMP>".."</SAMP> path
    segments; <EM>i.e.</EM>, whether they are prohibited, treated as
    ordinary path 
    segments or interpreted in accordance with the relative URL
    specification [<A HREF="#[7]">7</A>];
   </LI>
   <LI>define any limits of the implementation, including limits on path or
    search string lengths, and limits on the volume of header data the server
    will parse.
   </LI><!-- ##### Move the field resolution/translation para below here -->
  </OL>
  <P>
  Servers MAY generate the
  Script-URI in
  any way from the client URI,
  or from any other data (but the behaviour SHOULD be documented).
  </P>
  <P>
  For non-parsed header (NPH) scripts (see
  <A HREF="#7.1">section 7.1</A>), servers SHOULD
  attempt to ensure that the script input comes directly from the
  client, with minimal buffering. For all scripts the data will be
  as supplied by the client.
  </P>

  <H3>
   <A NAME="8.3">
    8.3. Summary of
    MetaVariables
   </A>
  </H3>
  <P>
  Servers MUST provide the following
  metavariables to
  scripts.  See the individual descriptions for exceptions and semantics.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    CONTENT_LENGTH (section <A HREF="#6.1.2">6.1.2</A>)
    CONTENT_TYPE (section <A HREF="#6.1.3">6.1.3</A>)
    GATEWAY_INTERFACE (section <A HREF="#6.1.4">6.1.4</A>)
    PATH_INFO (section <A HREF="#6.1.6">6.1.6</A>)
    QUERY_STRING (section <A HREF="#6.1.8">6.1.8</A>)
    REMOTE_ADDR (section <A HREF="#6.1.9">6.1.9</A>)
    REQUEST_METHOD (section <A HREF="#6.1.13">6.1.13</A>)
    SCRIPT_NAME (section <A HREF="#6.1.14">6.1.14</A>)
    SERVER_NAME (section <A HREF="#6.1.15">6.1.15</A>)
    SERVER_PORT (section <A HREF="#6.1.16">6.1.16</A>)
    SERVER_PROTOCOL (section <A HREF="#6.1.17">6.1.17</A>)
    SERVER_SOFTWARE (section <A HREF="#6.1.18">6.1.18</A>)
  </PRE>
  <P>
  Servers SHOULD define the following
  metavariables for scripts.
  See the individual descriptions for exceptions and semantics.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    AUTH_TYPE (section <A HREF="#6.1.1">6.1.1</A>)
    REMOTE_HOST (section <A HREF="#6.1.10">6.1.10</A>)
  </PRE>
  <P>
  In addition, servers SHOULD provide
  metavariables for all fields present
  in the HTTP request header, with the exception of those involved with
  access control.  Servers MAY at their discretion provide
  metavariables
  for access control fields.
  </P>
  <P>
  Servers MAY define the following
  metavariables.  See the individual
  descriptions for exceptions and semantics.
  </P><!--#if expr="! $GUI" -->
  <P></P><!--#endif -->
  <PRE>
    PATH_TRANSLATED (section <A HREF="#6.1.7">6.1.7</A>)
    REMOTE_IDENT (section <A HREF="#6.1.11">6.1.11</A>)
    REMOTE_USER (section <A HREF="#6.1.12">6.1.12</A>)
  </PRE>
  <P>
  Servers MAY
  at their discretion define additional implementation-specific
  extension metavariables
  provided their names do not
  conflict with defined header field names.  Implementation-specific
  metavariable names SHOULD
  be prefixed with "X_" (<EM>e.g.</EM>,
  "X_DBA") to avoid the potential for such conflicts.
  </P>

  <H2>
   <A NAME="9.0">
    9. 
    Script Implementation
   </A>
  </H2>
  <P>
  This section defines the requirements and recommendations for scripts
  that are intended to function in a CGI/1.1 environment.  It is intended
  primarily as a reference for script authors, but server implementors
  should be familiar with these issues as well.
  </P>

  <H3>
   <A NAME="9.1">
    9.1. Requirements for Scripts
   </A>
  </H3>
  <P>
  Scripts using the parsed-header method to communicate with servers
  MUST supply a response header to the server.
  (See <A HREF="#7.0">section 7</A>.)
  </P>
  <P>
  Scripts using the NPH method to communicate with servers MUST
  provide complete HTTP responses, and MUST use the value of the
  SERVER_PROTOCOL metavariable
  to determine the appropriate format.
  (See <A HREF="#7.1">section 7.1</A>.)
  </P>
  <P>
  Scripts MUST check the value of the REQUEST_METHOD
  metavariable in order
  to provide an appropriate response.
  (See <A HREF="#6.1.13">section 6.1.13</A>.)
  </P>
  <P>
  Scripts MUST be prepared to handled URL-encoded values in
  metavariables.
  In addition, they MUST recognise both "+" and "%20" in URL-encoded
  quantities as representing the space character.
  (See <A HREF="#3.1">section 3.1</A>.)
  </P>
  <P>
  Scripts MUST ignore leading zeros in the major and minor version numbers
  in the GATEWAY_INTERFACE
  metavariable value. (See
  <A HREF="#6.1.4">section 6.1.4</A>.)
  </P>
  <P>
  When processing requests that include a
  message-body, scripts
  MUST NOT read more than CONTENT_LENGTH bytes from the input stream.
  (See sections <A HREF="#6.1.2">6.1.2</A> and <A HREF="#6.2">6.2</A>.)
  </P>

  <H3>
   <A NAME="9.2">
    9.2. Recommendations for Scripts
   </A>
  </H3>
  <P>
  Servers may interrupt or terminate script execution at any time
  and without warning, so scripts SHOULD be prepared to deal with
  abnormal termination.
  </P>
  <P>
  Scripts MUST
  reject with
  error '405 Method Not
  Allowed' requests
  made using methods that they do not support. If the script does
  not intend
  processing the PATH_INFO data, then it SHOULD reject the request with
  '404 Not
  Found' if PATH_INFO is not NULL.
  </P>
  <P>
  If a script is processing the output of a form, it SHOULD 
  verify that the CONTENT_TYPE
  is "<SAMP>application/x-www-form-urlencoded</SAMP>" [<A HREF="#[2]">2</A>]
  or whatever other media type is expected.
  </P>
  <P>
  Scripts parsing PATH_INFO,
  PATH_TRANSLATED, or SCRIPT_NAME
  SHOULD be careful
  of void path segments ("<SAMP>//</SAMP>") and special path segments
  (<SAMP>"."</SAMP> and
  <SAMP>".."</SAMP>). They SHOULD either be removed from the path before
  use in OS 
  system calls, or the request SHOULD be rejected with
  '404 Not Found'.
  </P>
  <P>
  As it is impossible for 
  scripts to determine the client URI that
  initiated  a
  request without knowledge of the specific server in
  use, the script SHOULD NOT return "<SAMP>text/html</SAMP>"
  documents containing
  relative URL links without including a "<SAMP>&lt;BASE&gt;</SAMP>"
  tag in the document.
  </P>
  <P>
  When returning header fields, 
  scripts SHOULD try to send the CGI
  header fields (see section
  <A HREF="#7.2">7.2</A>) as soon as possible, and
  SHOULD send them
  before any HTTP header fields. This may
  help reduce the server's memory requirements.
  </P>
  
  <H2>
   <A NAME="10.0">
    10. System Specifications
   </A>
  </H2>

  <H3>
   <A NAME="10.1">
    10.1. AmigaDOS
   </A>
  </H3>
  <P>
  The implementation of the CGI on an AmigaDOS operating system platform
  SHOULD use environment variables as the mechanism of providing
  request metadata to CGI scripts.
  </P>
  <DL>
   <DT><STRONG>Environment variables</STRONG>
   </DT>
   <DD>
    <P>
    These are accessed by the DOS library routine <SAMP>GetVar</SAMP>. The
    flags argument SHOULD be 0. Case is ignored, but upper case is
    recommended for compatibility with case-sensitive systems.
    </P>
   </DD>
   <DT><STRONG>The current working directory</STRONG>
   </DT>
   <DD>
    <P>
    The current working directory for the script is set to the directory
    containing the script.
    </P>
   </DD>
   <DT><STRONG>Character set</STRONG>
   </DT>
   <DD>
    <P>
    The US-ASCII character set is used for the definition of environment
    variable names and header
    field names; the newline (NL) sequence is LF;
    servers SHOULD also accept CR LF as a newline.
    </P>
   </DD>
  </DL>
  
  <H3>
   <A NAME="10.2">
    10.2. Unix
   </A>
  </H3>
  <P>
  The implementation of the CGI on a UNIX operating system platform
  SHOULD use environment variables as the mechanism of providing
  request metadata to CGI scripts.
  </P>
  <P>
  For Unix compatible operating systems, the following are defined:
  </P>
  <DL>
   <DT><STRONG>Environment variables</STRONG>
   </DT>
   <DD>
    <P>
    These are accessed by the C library routine <SAMP>getenv</SAMP>.
    </P>
   </DD>
   <DT><STRONG>The command line</STRONG>
   </DT>
   <DD>
    <P>
    This is accessed using the
    <SAMP>argc</SAMP> and <SAMP>argv</SAMP>
    arguments to <SAMP>main()</SAMP>. The words have any characters
    that
    are 'active' in the Bourne shell escaped with a backslash.
    If the value of the QUERY_STRING
    metavariable
    contains an unencoded equals-sign '=', then the command line
    SHOULD NOT be used by the script.
    </P>
   </DD>
   <DT><STRONG>The current working directory</STRONG>
   </DT>
   <DD>
    <P>
    The current working directory for the script
    SHOULD be set to the directory
    containing the script.
    </P>
   </DD>
   <DT><STRONG>Character set</STRONG>
   </DT>
   <DD>
    <P>
    The US-ASCII character set is used for the definition of environment
    variable names and header field names; the newline (NL) sequence is LF;
    servers SHOULD also accept CR LF as a newline.
    </P>
   </DD>
  </DL>
  
  <H2>
   <A NAME="11.0">
    11. Security Considerations
   </A>
  </H2>

  <H3>
   <A NAME="11.1">
    11.1. Safe Methods
   </A>
  </H3>
  <P>
  As discussed in the security considerations of the HTTP
  specifications [<A HREF="#[3]">3</A>,<A HREF="#[8]">8</A>], the
  convention has been established that the 
  GET and HEAD methods should be 'safe'; they should cause no
  side-effects and only have the significance of resource retrieval.
  </P>
  <P>
  CGI scripts are responsible for enforcing any HTTP security considerations
  [<A HREF="#[3]">3</A>,<A HREF="#[8]">8</A>]
  with respect to the protocol version level of the request and
  any side effects generated by the scripts on behalf of
  the server.  Primary
  among these
  are the considerations of safe and idempotent methods.  Idempotent
  requests are those that may be repeated an arbitrary number of times
  and produce side effects identical to a single request.
  </P>
  
  <H3>
   <A NAME="11.2">
    11.2. HTTP Header
    Fields Containing Sensitive Information
   </A>
  </H3>
  <P>
  Some HTTP header fields may carry sensitive information which the server
  SHOULD NOT pass on to the script unless explicitly configured to do
  so. For example, if the server protects the script using the
  "<SAMP>Basic</SAMP>"
  authentication scheme, then the client will send an
  "<SAMP>Authorization</SAMP>"
  header field containing a username and password. If the server, rather
  than the script, validates this information then the password SHOULD
  NOT be passed on to the script <EM>via</EM> the HTTP_AUTHORIZATION
  metavariable
  without careful consideration.
  This also applies to the
  Proxy-Authorization header field and the corresponding
  HTTP_PROXY_AUTHORIZATION
  metavariable.
  </P>
  
  <H3>
   <A NAME="11.3">
    11.3. Script
    Interference with the Server
   </A>
  </H3>
  <P>
  The most common implementation of CGI invokes the script as a child
  process using the same user and group as the server process. It
  SHOULD therefore be ensured that the script cannot interfere with the
  server process, its configuration, or documents.
  </P>
  <P>
  If the script is executed by calling a function linked in to the
  server software (either at compile-time or run-time) then precautions
  SHOULD be taken to protect the core memory of the server, or to
  ensure that untrusted code cannot be executed.
  </P>
  
  <H3>
   <A NAME="11.4">
    11.4. Data Length and Buffering Considerations
   </A>
  </H3>
  <P>
  This specification places no limits on the length of message-bodies
  presented to the script.  Scripts should not assume that statically
  allocated buffers of any size are sufficient to contain the entire
  submission at one time.  Use of a fixed length buffer without careful
  overflow checking may result in an attacker exploiting 'stack-smashing'
  or 'stack-overflow' vulnerabilities of the operating system.
  Scripts may spool large submissions to disk or other buffering media,
  but a rapid succession of large submissions may result in denial of
  service conditions.  If the CONTENT_LENGTH of a message-body is larger
  than resource considerations allow, scripts should respond with an
  error status appropriate for the protocol version; potentially applicable
  status codes include '503 Service Unavailable' (HTTP/1.0 and HTTP/1.1),
  '413 Request Entity Too Large' (HTTP/1.1), and
  '414 Request-URI Too Long' (HTTP/1.1).
  </P>

  <H3>
   <A NAME="11.5">
    11.5. Stateless Processing
   </A>
  </H3>
  <P>
  The stateless nature of the Web makes each script execution and resource
  retrieval independent of all others even when multiple requests constitute a
  single conceptual Web transaction.  Because of this, a script should not
  make any assumptions about the context of the user-agent submitting a
  request.  In particular, scripts should examine data obtained from the client
  and verify that they are valid, both in form and content, before allowing
  them to be used for sensitive purposes such as input to other
  applications, commands, or operating system services.  These uses
  include, but are not
  limited to: system call arguments, database writes, dynamically evaluated
  source code, and input to billing or other secure processes.  It is important
  that applications be protected from invalid input regardless of whether
  the invalidity is the result of user error, logic error, or malicious action.
  </P>
  <P>
  Authors of scripts involved in multi-request transactions should be
  particularly cautios about validating the state information;
  undesirable effects may result from the substitution of dangerous
  values for portions of the submission which might otherwise be
  presumed safe.  Subversion of this type occurs when alterations
  are made to data from a prior stage of the transaction that were
  not meant to be controlled by the client (<EM>e.g.</EM>, hidden
  HTML form elements, cookies, embedded URLs, <EM>etc.</EM>).
  </P>

  <H2>
   <A NAME="12.0">
    12. Acknowledgements
   </A>
  </H2>
  <P>
  This work is based on a draft published in 1997 by David R. Robinson,
  which in turn was based on the original CGI interface that arose out of
  discussions on the <EM>www-talk</EM> mailing list. In particular,
  Rob McCool, John Franks, Ari Luotonen,
  George Phillips and
  Tony Sanders deserve special recognition for their efforts in
  defining and implementing the early versions of this interface.
  </P>
  <P>
  This document has also greatly benefited from the comments and
  suggestions made by  Chris Adie, Dave Kristol,
  Mike Meyer, David Morris, Jeremy Madea,
  Patrick M<SUP>c</SUP>Manus, Adam Donahue,
  Ross Patterson, and Harald Alvestrand.
  </P>
  
  <H2>
   <A NAME="13.0">
    13. References
   </A>
  </H2>
  <DL COMPACT>
   <DT><A NAME="[1]">[1]</A>
   </DT>
   <DD>Berners-Lee, T., 'Universal Resource Identifiers in WWW: A
       Unifying Syntax for the Expression of Names and Addresses of
       Objects on the Network as used in the World-Wide Web', RFC 1630,
       CERN, June 1994.
       <P>
       </P>
   </DD>
   <DT><A NAME="[2]">[2]</A>
   </DT>
   <DD>Berners-Lee, T. and Connolly, D., 'Hypertext Markup Language -
        2.0', RFC 1866, MIT/W3C, November 1995.
       <P>
       </P>
   </DD>
   <DT><A NAME="[3]">[3]</A>
   </DT>
   <DD>Berners-Lee, T., Fielding, R. T. and Frystyk, H.,
          'Hypertext Transfer Protocol -- HTTP/1.0', RFC 1945, MIT/LCS,
          UC Irvine, May 1996.
       <P>
       </P>
   </DD>

  <DT><A NAME="[4]">[4]</A>
  </DT>
  <DD>Berners-Lee, T., Fielding, R., and Masinter, L., Editors,
   'Uniform Resource Identifiers (URI): Generic Syntax', RFC 2396,
   MIT, U.C. Irvine, Xerox Corporation, August 1996.
   <P>
   </P>
  </DD>

  <DT><A NAME="[5]">[5]</A>
  </DT>
  <DD>Braden, R., Editor, 'Requirements for Internet Hosts --
          Application and Support', STD 3, RFC 1123, IETF, October 1989.
       <P>
       </P>
   </DD>
   <DT><A NAME="[6]">[6]</A>
   </DT>
   <DD>Crocker, D.H., 'Standard for the Format of ARPA Internet Text 
          Messages', STD 11, RFC 822, University of Delaware, August 1982.
       <P>
       </P>
   </DD>
  <DT><A NAME="[7]">[7]</A>
  </DT>
  <DD>Fielding, R., 'Relative Uniform Resource Locators', RFC 1808,
          UC Irvine, June 1995.
       <P>
       </P>
   </DD>
   <DT><A NAME="[8]">[8]</A>
   </DT>
   <DD>Fielding, R., Gettys, J., Mogul, J., Frystyk, H. and
          Berners-Lee, T., 'Hypertext Transfer Protocol -- HTTP/1.1',
          RFC 2068, UC Irvine, DEC,
	  MIT/LCS, January 1997.
       <P>
       </P>
   </DD>
   <DT><A NAME="[9]">[9]</A>
   </DT>
   <DD>Freed, N. and Borenstein N., 'Multipurpose Internet Mail
          Extensions (MIME) Part Two: Media Types', RFC 2046, Innosoft,
          First Virtual, November 1996.
       <P>
       </P>
   </DD>
   <DT><A NAME="[10]">[10]</A>
   </DT>
   <DD>Mockapetris, P., 'Domain Names - Concepts and Facilities',
          STD 13, RFC 1034, ISI, November 1987.
       <P>
       </P>
   </DD>
   <DT><A NAME="[11]">[11]</A>
   </DT>
   <DD>St. Johns, M., 'Identification Protocol', RFC 1431, US
          Department of Defense, February 1993.
       <P>
       </P>
   </DD>
   <DT><A NAME="[12]">[12]</A>
   </DT>
   <DD>'Coded Character Set -- 7-bit American Standard Code for
          Information Interchange', ANSI X3.4-1986.
       <P>
       </P>
   </DD>
   <DT><A NAME="[13]">[13]</A>
   </DT>
   <DD>Hinden, R. and Deering, S.,
          'IP Version 6 Addressing Architecture', RFC 2373,
	  Nokia, Cisco Systems,
          July 1998.
       <P>
       </P>
   </DD>
  </DL>
  
  <H2>
   <A NAME="14.0">
    14. Authors' Addresses
   </A>
  </H2>
  <ADDRESS>
   <P>
   Ken A L Coar
   <BR>
   MeepZor Consulting
   <BR>
   7824 Mayfaire Crest Lane, Suite 202
   <BR>
   Raleigh, NC   27615-4875
   <BR>
   U.S.A.
   </P>
   <P>
   Tel: +1 (919) 254.4237
   <BR>
   Fax: +1 (919) 254.5250
   <BR>
   Email:
   <A
    HREF="mailto:Ken.Coar@Golux.Com"
   ><SAMP>Ken.Coar@Golux.Com</SAMP></A>
   </P>
  </ADDRESS>
  <ADDRESS>
   <P>
   David Robinson
   <BR>
   E*TRADE UK Ltd
   <BR>
   Mount Pleasant House
   <BR>
   2 Mount Pleasant
   <BR>
   Huntingdon Road
   <BR>
   Cambridge CB3 0RN
   <BR>
   UK
   </P>
   <P>
   Tel: +44 (1223) 566926
   <BR>
   Fax: +44 (1223) 506288
   <BR>
   Email:
   <A
    HREF="mailto:drtr@etrade.co.uk"
   ><SAMP>drtr@etrade.co.uk</SAMP></A>
  </ADDRESS>
  
 </BODY>
</HTML>