GDK error codes

["Timothy M. Shead" <tshead k-3d com>]

One of my users gets the following when running an application using 
GTK+ 1.2, and I'm wondering what the meanings of the error codes are; 
not so much what these specific codes are, but what they represent, so I 
know where to look them up in the future.

Gdk-ERROR **: BadFont (invalid Font parameter)
  serial 23366 error_code 7 request_code 143 minor_code 12

Thanks in advance,
Timothy M. Shead
tshead k-3d com