Is it proper or ever acceptable to use the word "spelt" as in, "That word is spelt incorrectly." or should it always be, "That word is spelled incorrectly."
Maybe they have some residual use as adjectives:
"She trimmed off the burnt portion of the cake," but not "The cake was burnt on the outside."
Possibly "A long list of ill-spelt words" but not "many words were spelt wrong."
Not so much that it's wrong, just that it's not ever seen any more.