/format documentation?

hi all!
first the story: some friend of mine gave me a script, that script changed
some things in /format. we didn't see the "reset" option at first and
ended up guessing the right /format strings and searching a documentation
on irssi.org until we tried out /format and /format help.
so my question is: *is* there some documentation for /format? if there is,
then: where? (if there is not, i'd try to get some information about it
since i believe it is really useful and a lot of fun, and maybe get the
chance to write that documentation.)
i hope you can help me with that.

leonie