Yep, that just emphasises how stupid the standard is. Others have mentioned Westward Ho![0] which is in England and contains a non-alphanumeric character.
For Wales for sure, often there are two versions of the place name, the Welsh, and an English butchering of it (see for example Pont-y-pŵl, which is spelt Pontypool in English), so I suppose it would be the English thing to do to simply pretend the Welsh/Irish spelling doesn't matter, and only use the English spelling (a little tongue-in-cheek from my side, but sadly likely the reality).
However, I suspect that whoever authored the standard was just sloppy and wrote 'alphanumeric' without giving it any careful thought.
For Wales for sure, often there are two versions of the place name, the Welsh, and an English butchering of it (see for example Pont-y-pŵl, which is spelt Pontypool in English), so I suppose it would be the English thing to do to simply pretend the Welsh/Irish spelling doesn't matter, and only use the English spelling (a little tongue-in-cheek from my side, but sadly likely the reality).
However, I suspect that whoever authored the standard was just sloppy and wrote 'alphanumeric' without giving it any careful thought.
[0]: https://en.wikipedia.org/wiki/Westward_Ho!