Specific Schemes

The mapping for some existing standard and experimental protocols is outlined in the BNF syntax definition . Notes on particular protocols follow. The schemes covered are
http
Hypertext Transfer Protocol
ftp
File Transfer protocol
gopher
The Gopher protocol
mailto
Electronic mail address
mid
Message identifiers for electronic mail
cid
Content identifiers for MIME body part
news
Usenet news
nntp
Usenet news for local NNTP access only
prospero
Access using the prospero protocols
telnet , rlogin and tn3270
Reference to interactive sessions
wais
Wide Area Information Servers
Other schemes may be specified by future specifications

New schemes may be registered at a later time.