I think I was little too terse with the description. :) What I see missing is function arguments and function privileges. Functions (both UDF, UDR and SQL) are there, as far as I can tell.

Did I miss something @FransBouma, @gonline?

I only support the reverse engineering of stored procs on firebird so looks good to me :)
For people who want to do that for functions: function arguments and return types is key I think. So names and types and ordinal position of the arguments, as well as the type returned by a function. Privileges might not be that useful, at least I can't see a use case for that, but if you can obtain that regardless, returning it wouldn't hurt