Error Messages from GNUPGP Shell

[Joel N. Weber II]

   i've been developing a java application which passes
   data to the gnupgp shell to sign,verify,encrypt and
   decrypt data. Currently, i am parsing the return
   strings from gnupgp and return a special code for each
   message, however - im not aware of all possibil return
   messages from gnupgp - so there may be some ive
   forgotten...can i find somewhere a list of all
   messages with a description when this message will be
   appear ?

   To bad, that even with --verbose i dont get exact
   informations like SIGN OK or DECRYPT FAILED...

Are you familiar with --status-fd?  Have you looked at
gnupg-1.2.0/doc/DETAILS?