Country names and grammar, What the hell is the adjective form? Options

[Penta]

Okay. A question that suddenly arose in my mind during a boring bus ride today.

What the hell is the adjective form of UCAS? Or CAS? Or Tir Tairngire? (Or worse, Tir na Nog)

It's a common complaint I have about sci-fi (or fantasy) country/state names - there's no allowance for non-noun forms.

To wit, in English there's usually an adjective form of a country name. The USA gets "American", the UK "British", Saudi Arabia "Saudi". And so on and so forth.

Except with future countries. FASA/FanPro/CGL made it worse by creating countries where both could conceivably use the same damn adjective (see UCAS and CAS), or where the name isn't in any real language, so we can't even derive the adjective form.

For UCAS:

"UCASian" is like "USAian", a horrific mangling of the language for political correctness. "Canadian-American" has the problem of being rather unwieldy and sounding more like a personal descriptor.

It actually gets no better a lot worse with corporations being nationalities, now, of a sort.

Are you a "Shiawasian"? A "Saeder-Kruppian"?

Gah.

I can be liberal on many things, but (and maybe it's me) this drives me batty.