[d1sxeyes]

Standards are just that. You can say that you can standards are the 'minimum, not the maximum', but if the standard says only alphanumeric characters are permitted (and it turns out this isn't a very well written standard, so there's a load of discussion possible on this point), an implementation that allows non-alphanumeric characters is wrong.

As a thought experiment, how far beyond the 'maximum' is acceptable? Latin letters with diacritics? Cyrillic letters? Arabic letters? Chinese logographs? Emojis? Would you expect all systems which are standard-compliant to be able to handle all of the above?

[rhplus]

The UK includes Wales and Northern Ireland, both of which have place names that include diacritics. Whether or not Wales and Northern Ireland choose to follow this particular British Standard, I don’t know. Some examples here:

https://english.stackexchange.com/questions/111148/do-any-uk...

[d1sxeyes]

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.

[0]: https://en.wikipedia.org/wiki/Westward_Ho!