[chirp_users] What it does and how ?

Is there a repository of information about what exactly chirp does and how to use ?

It looks like native chirp files do not apply to 91/92 radios. Just looking for a what is what page.

Also it seems when I export from a 91 / 92 to csv, then use open office calc to edit the file, that there is a data mismatch error trying to re-open in chirp, even if I don't (knowingly) change anything.

TNX and 73, Steve