>I see your point, but seems it conflicts with documented type() behavior: it should return "U" in this case.

Oh, okay, now I get your point. Hmm, weird. Looks like a doc bug to me. Look under VARTYPE(), and it's documented there, sort of. Given that TYPE() doesn't have a choice of "X" for the var type, I guess it just doesn't return anything. Note that VARTYPE() behaves the same way if you specify .t. for the second parameter.