URI
RFC1630 : Universal Resource Identifiers in WWW
RFC1738 : Uniform Resource Locators (URL)
RFC1808 : Relative Uniform Resource Locators
RFC2396 : Uniform Resource Identifiers (URI): Generic Syntax
RFC2169 : A Trivial Convention for using HTTP in URN Resolution (THTTP)
RFC2368 : The mailto URL scheme
finger URL
URI schemes (IANA) : Uniform Resource Identifier (URI) SCHEMES

HTTP
RFC1945 : Hypertext Transfer Protocol -- HTTP/1.0
RFC2068 : Hypertext Transfer Protocol -- HTTP/1.1
RFC2616 : Hypertext Transfer Protocol -- HTTP/1.1
RFC2617 : HTTP Authentication: Basic and Digest Access Authentication
RFC2069 : An Extension to HTTP : Digest Access Authentication
CGI/1.1
RFC2109 : HTTP State Management Mechanism (Cookie)
Client Side State - HTTP Cookies
A Standard for Robot Exclusion (/robots.txt)

HTML
HTML 4.0 Specification
RFC1866 : Hypertext Markup Language - 2.0
RFC2070 : Internationalization of the Hypertext Markup Language

LDAP
RFC1777 : Lightweight Directory Access Protocol
RFC1959 : An LDAP URL Format

Gopher
RFC1436 : The Internet Gopher Protocol (a distributed document search and retrieval protocol)

Wais
RFC1625 : WAIS over Z39.50-1988

FTP
RFC0959 : FILE TRANSFER PROTOCOL (FTP)
RFC1579 : Firewall-Friendly FTP
Extensions to FTP
Extensions to FTP

Telnet
RFC0854 : Telnet Protocol Specification
RFC0855 : Telnet Option Specifications
RFC0856 : Telnet Binary Transmission
RFC0857[Echo] | RFC0858[SuppressGoAhead] | RFC0859[Status] | RFC0860[TimingMark] | RFC0861[List]

NNTP
RFC0977 : Network News Transfer Protocol -- A Proposed Standard for the Stream-Based Transmission of News
extensions : Common NNTP Extensions
RFC1036 : Standard for Interchange of USENET Messages

SMTP
RFC0821 : SIMPLE MAIL TRANSFER PROTOCOL
RFC0822 : STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT MESSAGES
RFC2554 : SMTP Service Extension for Authentication
RFC2595 : AUTH PLAIN

POP
RFC1460 : Post Office Protocol - Version 3

IMAP
RFC2060 : INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1

LPR
RFC1179 : Line Printer Daemon Protocol

X Window
RFC1013 : X WINDOW SYSTEM PROTOCOL, VERSION 11 -- Alpha Update

MIME (Multipurpose Internet Mail Extensions)
RFC2045 (body) : MIME Part One: Format of Internet Message Bodies
RFC2046 (types) : MIME Part Two: Media Types
RFC2047 (header) : MIME Part Three: Message Header Extensions for Non-ASCII Text
RFC2231 (parameter-value) : MIME Parameter Value and Encoded-Word Extensions: Character Sets, Languages, and Conditions.
IANA: media-types
IANA: character-sets

Ident
RFC1413 : Identification Protocol

DNS
RFC1034 : Domain Names - Concepts and Facilities
RFC1035 : Domain Names - Implementation and Specification

Private IP
RFC1597 : Address Allocation for Private Internets

Socks
socks : NEC SOCKS site
RFC1928 : SOCKS Protocol Version 5
RFC1961 : GSS-API Authentication Method for SOCKS Version 5
RFC1929 : Username/Password Authentication for SOCKS V5
RFC1508 : Generic Security Service Application Program Interface (GSSAPI)

SSL
RFC2487 : SMTP Service Extension for Secure SMTP over TLS
RFC2595 : Using TLS with IMAP, POP3 and ACAP
draft-murray-auth-ftp-ssl-16 : Securing FTP with TLS
SSLeay

ICP
RFC2186: Internet Cache Protocol (ICP), version 2
RFC2187: Application of Internet Cache Protocol (ICP), version 2
ICP : Internet Cache Protocol

PGP
RFC1991: PGP Message Exchange Formats
RFC1847: Security Multiparts for MIME: Multipart/Signed and Multipart/Encrypted
RFC1848: MIME Object Security Services
RFC2015: MIME Security with Pretty Good Privacy (PGP)
RFC2015: PGP/MIME home