When trying to decide whether a match was case sensitive or not, all I could find in the documentation was "the PCRE_CASELESS option is set when the matching is required to be case-insensitive." It seems that PCRE_CASELESS is set for this condition
condition=${if or {{match{$header_subject:}{Out of Office Autoreply}} {match{$header_subject:}{Auto Reply Message}}} {true}{false} }
I can't tell from the documentation whether PCRE_CASELESS should be set for match conditions and i had to determine that experimentally. Is that information in the documentation and I just haven't found it or is it an omission?
Also, it would be nice if chapter 8 referred us to 'man pcre' instead of just a book for the pcre syntax. It seems obvious, but i didn't think of it immediately and it would have saved me some time.