> Only Americans (to the extent I know) differentiate jail and gaol. Jail and prison.
You inhabit a very different reality than everybody else. Americans do not differentiate jail and gaol; Americans don't use the word "gaol" under any circumstances, ever. It is not a part of American English.
It's a common spelling in fantasy video games and books, but it feels kind of performative.
These same games will have voice actors pronounce "ye" as it's written, unaware that the y is a typographic substitute for Þ. "ye olde" is pronounced "the old". But likewise, there's some VAs that clearly only ever read a word, like in the newer God of War games where a character mangles "prescient".
Same had to actually look it up and at least Merriam-Webster lists the word as “chiefly British spellings of JAIL, JAILER”. Which at least hints that the dictionary writers thought it is less common out side of Britain.
I graduated from high school and even got a bachelor's degree. I've read several books written before last year, and have talked to dozens of people. I've never heard or seen the word gaol. And if I had, I'd probably assume it was "goal" misspelled. I make no assertions of being particularly smart or literate, but only typical.
Knowing the word exists is a different thing than using it in daily speech. I, and I'm sure most people, would be very surprised to hear there are populations of the USA where "gaol" is used regularly.
I apologise for mixing terms. Jail and Prison? Do you disagree this is a point of difference? Americans also don't seem to talk about being on remand. In police custody is unwieldy, I agree.
As int_19h notes, there are people (in the US) who believe that there is a difference between the meaning of the word "jail" and the meaning of the word "prison". And as int_19h also notes, those people are wrong; Americans will just be confused if you try to use the words differently. It's similar to the insistence of a group with near-perfect overlap that crimes for which jail time isn't a possible punishment can't be correctly referred to as "crimes".
You inhabit a very different reality than everybody else. Americans do not differentiate jail and gaol; Americans don't use the word "gaol" under any circumstances, ever. It is not a part of American English.