Our library (running Mandarin currently) has a limit of two DVDs per household. Mandarin doesn't enforce this limit; the librarian knows pretty much everybody in this little town and has the data in her head. But we volunteers don't have that brainpower. I have been working on a Koha upgrade for our library for some months, and am pretty close to having everything working. But this household limit has me a bit stumped. For one thing, our patron database is a bit inconsistent, so if we define "household" as being "all borrowers with the same address", we're in trouble because the same address might be spelled several different ways. (For example, Route can be RT or RTE or Rte. or Rt. or Rt) But leaving aside the consistency problem, Koha doesn't seem to have a way to do this kind of check. I can cobble together some SQL that looks like this: select count(issue_id) from issues left join borrowers on issues.borrowernumber = borrowers.borrowernumber left join items on issues.itemnumber = items.itemnumber where borrowers.address = '123 Main Street' and city = 'Podunk' and state = 'VT' and items.itype = 'DVD'; and then check this result against configurable checkout limits for particular item types. This sounds like a fair amount of work in the Koha codebase itself, so I was wondering if anybody else had looked into this and had other ideas.