[Users] File containing filter rules?

[Malachi Constant]

I have a rather larger number of filter rules, and would like to search
through them to locate a particular item.  I can of course go to

    Configuration -> Filtering

and then scroll through the list.  But since the list is long, doing so
is (a) tedious, and (b) unreliable (I'm likely to miss something).

The rules must be contained in a file somewhere, mustn't they?  I
should like to have a file --- ascii, or something that can readily be
converted to ascii, would be preferred --- that I could search through
with, say, a text editor.

Might it be possible to obtain such a file?  If so how?  I can find no
trace of such a file in ~/.claws-mail.

sincerely,

Unk