This seems like a great place to observe that Magic The Gathering is Turing-complete. If your requirements suggest that MTG is a programming language, but HTML

This seems like a great place to observe that Magic The Gathering is Turing-complete. If your requirements suggest that MTG is a programming language, but HTML isn't, they're probably bad requirements. The syntax/semantics/instructions option seems like a way better basis. And honestly, most of us can get by with a Potter Stewart style standard of "know it when I see it".