Yes that's right but when you forget it or don't know it's needed it can cause hours of frustration till you realise! Just a quick note in the help text is all that's needed.
Is that non-literal strings? Not sure what it means otherwise.
It's just that when you get the problem you don't necessarily know/remember about the underscore/ obfuscation. A couple of words in the help text would save many hours frustration. It's happened to me two/ three times so far.