Suppose one answers a code-golf challenge for a language with a solution which is ill-formed according to the spec of the selected language.
"But it works nonetheless with all major interpreters".
Is the answer considered valid?
Challenge: print this text:
Solution: HTML, 19 bytes:
Discussion: Most (all?) browser would indeed print the exact text
Hello, World!, even though the code snippet is not a valid HTML file. Should OP accept this answer?