Gunnar Morling no, I cannot see any practical use cases for this. Except maybe some specific numbers, where a digit represent some meaning and should be from a predefined set of digits. Maybe such cases could be applied to some identification numbers ?

There's this other PR with NumberPattern (547) which seems to be a better approach than making current @Pattern available for numbers. But again ... It may only be a better solution for the problem that does not really exist

It wasn't a huge amount of work so I wouldn't mind if it'll be rejected.