Not sure if I mentioned this before, but the first time I ever came across this for myself was when applying to the CAA for the initial JAA IR, Jan 2012, when it was discovered I did not have the Level 6 signed off. The IR examiner (CAA staff FE) did it then.
Maybe I had it from the various previous check flights etc but it doesn't look like anybody kept a record, and the CAA certainly didn't.