Complete docs for ExtractSubjectTagMatch?

I’m having some trouble with ExtractSubjectTagMatch or at least I
think I am. On some replies, the reply will open a brank new ticket
even though the ticket tag is clearly in the subject line. I’m having
trouble figuring out what is wrong.

Here’s an example:
[Support #49] Re: [Support #48] replace “Store Credit” with
"Credit" on invoices

Are there complete docs on how to do this appropriately? The wiki
seems quite minimal in this regard – most of the options have no
specific documentation.

I’m not asking anyone to help me get it right other than by pointing
me to complete docs, but if you are so inclined here is my current

Set( $rtname, ‘Support’ );
Set( $RTAddressRegexp, ‘^(abuse-support|support|tickets|ipadmin)$’ );
Set( $EmailSubjectTagRegex, qr/\Q(Support|Abuse)\E/i );
Set($ExtractSubjectTagMatch, qr/[.+? #\d+]/);
Set($ExtractSubjectTagNoMatch, ( ${RT::EmailSubjectTagRegex}
? qr/[(?:${RT::EmailSubjectTagRegex}) #\d+]/
: qr/[\Q$RT::rtname\E #\d+]/) );

Jo Rhett
Net Consonance : consonant endings by net philanthropy, open source
and other randomness