[asterisk-users] extensions.conf programming?

[Ken D'Ambrosio]

Hey, all.  I haven't really gotten deep into Asterisk since 1.0.x, and I'm
afraid I've forgotten a fair bit.  One big thing that I've forgotten is
the syntax, etc., for extensions.conf.  Where do I find that?  I'm looking
for stuff about commands, syntax for commands, variables, etc.  Is there a
handy-dandy manpage, webpage, or what-have-you that I'm missing?

Thanks!

-Ken