A while ago I did a bunch of GREP work on some excel files PD sent me to: divide one address field into StreetNum, StreetName and StreetNotes fields. In doing that I noticed that the pointers in that file to records in another table were out by a fixed number so modified that too.

Turns out that the file PD sent me had the address field sorted in the wrong order relative to all the other fields for each record, so he fixed that and I had to re-do the GREP. Having completed that I then set to do the renumbering and noticed that due to the new sorting, the pointers were now off by a gradually accumulating number, rather than a fixed number. It took half a day to get the pointers sorted out.

Sent the updated files to PD. He's satisfied everything's in order now.