[S]

1. SERVER_ADDRESS
2. SERVER_NAME
3. SERVER_NAME_LIST
4. SERVER_SOFTWARE
5. SF_ABBREV
6. SF_BYTES
7. SHOW_SERVER_DETAILS
8. SHOW_SERVER_VERSION
9. SHUT_WR
10. SPARE_FDS
11. STATS_TIME
12. STDERR_FILENO
13. STDIN_FILENO
14. STDOUT_FILENO
15. STRICT_XHTML
16. ST_BANG
17. ST_GROUND
18. ST_LESSTHAN
19. ST_MINUS1
20. ST_MINUS2