That sign says "One Way". Not "yes turns"... I don't think I've ever seen a sign saying that, actually, it's either "No Turns" or no sign at all, since by default turns are allowed.
I've definitely seen signs that say "you can turn here" and "you must turn here", admittedly not with language but with arrows (the "you can turn here" signs around here looking like a forwards arrow with a curved arrow bending off). They're not in general use, only for weird situations (like "two turning lanes" or "yes really this really strange intersection does work like this").
Probably regional though.