When http://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=12586 is pushed, the "required match checks" will work for Bibliographic records once again.

At the moment, match checks work on an "equal" comparison, but I'm thinking it might be useful to have additional comparisons like >, <, >=, <=, and !=. (Well, string and numeric comparison operators...) 

Example:

- Record 1b 005 > Record 1a 005
Import only if the record's 005 is newer than the existing record's 005.

Admittedly, that's the only feasible example I can think of off the top of my head at the moment.

I suppose you might require that the 942$c be "not equal" before updating, if you only want to update a subset of records that are missing some information. I suppose you should have figured that out beforehand and only tried importing the records you actually want to change.

You might try a match check where the 250 edition statement is > or < but since it's a free-text field, that would probably be a bad idea.

I suppose most cases of using additional comparison operators might be in regards to arbitrary data. Like maybe you only want to update target records if the match result has a 999$c < 1000 or something like that, but that seems unlikely and unwieldy at best.

Just throwing it out here as an idea. It could be useful for the 005 at least.