Many specifications for the Internet are published as so-called "requests for comments" or "Internet drafts". They can be browsed and searched via www.rfc-editor.org and www.ietf.org. I've collected some RFCs here in the hope that you need not search as long as I did. :-)
If the link to a draft on the IETF server doesn't work any longer, it often helps to increment the draft number in the URI once or twice and retry; old versions of draft documents are removed from the server.
HTTP/1.0 protocol: RFC1945
HTTP/1.1 protocol: RFC2616 (errata)
HTTP version numbering: RFC2145
HTTP authentication: RFC2617
HTTP extension framework: RFC2774
HTTP state management mechanism ("cookies"): RFC2965 (practice: RFC2964)
FTP: RFC959
FTP security extensions (the commands "AUTH", "PROT" etc.): RFC2228
FTP extension for IPv6 and NATs (the commands "EPRT" and "EPSV"): RFC2428
FTP security considerations ("bounce attack" with proxies; password
guessing): RFC2577
Firewall-friendly FTP: RFC1579
Anonymous FTP: RFC1635
FTP feature negotiation (the commands "FEAT" and "OPTS"): RFC2389
FTP i18n: RFC2640
FTP
extensions (draft #16, expired March 2003; the commands "MLSD", "MLST",
"SIZE" etc.)
Internet Message Format: RFC2822 (Usenet: RFC1036)
SMTP: RFC2821
Message Submission: RFC2476
POP3: RFC1939
(extensions: RFC2449; response
codes: RFC3206;
scheme: RFC2384)
IMAP4: RFC3501
(obsoletes RFC2060;
implementation recommendations: RFC2683; scheme: RFC2192; UIDPLUS
extension: RFC4315;
extension drafts)
AUTH extension for IMAP/POP: RFC2195
NNTP: RFC977; replacement
(draft #27, expired December 10, 2005); extensions: RFC2980; scheme
extension draft
Read
This Before You Write a Newsreader
TLS 1.0: RFC2246
(version
1.1 draft #13, expired December 2005)
TLS extensions: RFC3546
TLS compression methods: RFC3749
HTTP over TLS: RFC2818
HTTP/1.1 upgrade to TLS: RFC2817
Securing FTP with TLS: RFC4217 (information)
Using
TLS with NNTP (draft #9, expires March 2006)
TLS with IMAP/POP: RFC2595
SMTP over TLS: RFC3207
HMAC hashing: RFC2104
SSL 3.0 (draft
#2; an analysis)
Requirements for Internet hosts: RFC1123 (updated by RFC1349 and RFC2181)
Security Mechanisms for the Internet: RFC3631
Security Considerations: RFC3552
Crypto Attacks on Hashes: RFC4270
URIs: RFC3986
(updates/obsoletes RFC2396, RFC1738 and RFC1808; report: RFC3305; schemes: IANA, W3C)
Base64 encoding: RFC3548, 3.
MD5: RFC1321
UTF-8: RFC3629
Finger: RFC1288
Gopher: RFC1436
(URI: RFC4266;
tools/groups: RFC1689; Gopher+)
CGI (Common Gateway Interface): RFC3875; W3C
HTML 4.01 (errata)
JavaScript (experimental proposal 2.0)
IPv6: RFC2460;
addressing: RFC3513
(obsoletes RFC2373); basic socket
interface extensions: RFC3493 (obsoletes RFC2553, which
obsoletes RFC2133);
advanced API: RFC3542 (obsoletes RFC2292); application
transition: RFC4038
IRC: RFC2810
(client protocol: RFC2812)
Internet authentication: RFC1704
Internet Users' Glossary: RFC1983
The Twelve Networking Truths: RFC1925
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