Does Unicode have a code point for a garbled digit?

Question

I'm looking for a placeholder glyph to display "insert any digit here", to tersly communicate in limited GUI space that a range of numbers is meant.

For decimal numbers I would use x, e.g.

1xx - room numbers on first floor
2xx - room numbers on second floor

but my ranges are hexadecimal, so

0x00xx - IDs reserved for future use
0x01xx - IDs reserved for development
0x02xx - IDs managed by team Bravo

looks a bit odd, as the x would have two different meanings.

Answer 1

There is no Unicode character that simply means "any digit here". Unicode does offer an extensive range of symbols to choose from though, which will not be confused with 'x'. An underscore has the benefit that, in many fonts, it has the same width as a numeral. If you choose something more exotic, like ◌ DOTTED CIRCLE or ⯑ UNCERTAINTY SIGN, just ensure that it will be present in the font used for your interface.