Also, "Nauru".capitalize() should succeed as it has no official capital.
(tongue firmly in cheek ;)
"Switzerland".capitalize()
"HELVETICA"> Due to its linguistic diversity, Switzerland is known by a variety of native names: Schweiz [ˈʃvaɪts] (German);[note 5] Suisse [sɥis(ə)] (French); Svizzera [ˈzvittsera] (Italian); and Svizra [ˈʒviːtsrɐ, ˈʒviːtsʁɐ] (Romansh).[note 6] On coins and stamps, the Latin name, Confoederatio Helvetica – frequently shortened to "Helvetia" – is used instead of the four national languages.
* https://en.wikipedia.org/wiki/Switzerland
That's also why the ccTLD of Switzerland is .ch.
What you're seeing may be an 'artifact' of that.
"Switzerland".capitalize()
𝔈ℑ𝔇𝔊𝔈𝔑𝔒𝔖𝔖𝔈𝔑𝔖ℭℌ𝔄𝔉𝔗
One of those two is Switzerland, which has the official Latin name "Confoederatio Helvetica", leading zinekeller joke that the capital form was "HELVETICA". See https://en.wikipedia.org/wiki/Name_of_Switzerland .
I pretended my implementation of that non-extent programming language generated "Eidgenossenschaft", see https://en.wikipedia.org/wiki/Eidgenossenschaft . As that's a German word, I decided to use a blackletter typeface, specifically, the Fraktur in Unicode which is meant to encode mathematical alphanumeric symbols, then imply that my locale the reason I got a German word.
Edit: I now understand this to be a joke. But.., given the craziness that I've seen in the past, this doesn't seem out of the realm of plausibility!
And, in theory, two countries could share the same capital (as a condominium which is equal joint territory of both, or some kind of third territory belonging to neither), although I'm not aware that's ever actually happened. But, at the subnational level, it has happened in India – Chandigarh is the joint capital of two Indian states (Punjab and Chandigarh), each of which has it as its capital despite it being in neither of them, as well as being a union territory (and hence also capital of itself).