sodium thiosulfate was originally called hyposulfate of soda ( hypo )
it is not the same compound as speed fixer which is now, most commonly used
as fixer ...
so, while hypo is used for both film and prints it really depends what you are talking about
because speed fixer, what is now sold as fixer, is high capacity and FAST is commonly suggested
to be "hypo" .... its not the same thing ... and if you were playing some sort of wacky trivia game
and you just said "fixer" when asked " what is hypo" you might get it wrong .. ammonium thiosulfate is speed fixer ...
just thought of someting ...
maybe its called hyposulfate of ammonium so, its still called hypo?