Thanks for hosting this, Will. It's certainly been interesting to hear what's going on in other HE institutions, and given me some food for thought. Oh, and some words to look up - like RegEx! And, while we were having the discussions I had a quick trawl through our database and, as I suspected, we have a large proportion of monograph records that don't have ISBNs, principally because they pre-date the system, so, we have a lot of BNB number (e.g b1234567), LC numbers (e.g. <space>1234567<space>) and system assigned, local control numbers (e.g. M12345678LP, q1234567, w...... etc.) and this has always caused us issues with matches.
Anyway, thanks again,
Lynne