The RFC -> Request for Comments
If you want to write a
program to use an
internet protocol it is a good idea to actually read the RFC concerning the
standard for that protocol.
RFC's define the
interfaces between servers, formats for
e-mail, and how just about everything on the internet 'should' work. Should is the
operative word.
If you've never read an RFC, you really should... just like your wisdom
teeth... if you've never had them pulled, you really should!