If you might need to store multiple duplicate records or want a sequence number for the order of created/updated records in your table.

This is what you need, the big annoying bit is you need to also update this column on EVERY SINGLE UPDATE to that table and you'll want _A tables if you want to figure out historical ordering of events. And you will be creating a unique sequence for every single table where this column exists. but just shove that functionality in a trigger.

This also would be quite handy if you want a unique key handle for picking which records are being manually deleted and you have the solution when one person updates a record at the same time someone else is trying to delete a record.