When generating a global diff, that is, without specifying the files affected by the patch explicitly, some uninformative lines might be present in the output. A typical example occurs in CVS: it indicates files present in your local copy but otherwise unknown to the server with a question mark in diff outputs.
Patcher has a project option named :diff-line-filter that lets
filter out such unwanted lines. This must be a regular expression
matching a whole line. Caution however: do not put beginning or end of
lines markers in your regexp. Patcher will do it for you.