Dieter, although it doesn't seem especially logical, WikiTree never re-uses a number. This is driven by the WikiTree ID being the unique record index. After a merge takes place, the ID number that disappears is still used in the database as a re-direct to the new ID number to ensure not breaking any links that may already exist to the old ID from other profiles. Every time we create a profile, the highest current sequential number for the same LNAB is incremented by one.