What do you do when the OP says they only want RAW but the RAW don't mention what they want? I went for "tell them the RAW are silent but give them your humble (and indeed tongue-in-cheek) opinion for a solution, but that was almost instantly downvoted, and not by the OP. So I left it as "say the RAW are silent but cite the nearest thing (making it clear these are not the RAW you seek)."
Is is enough just to say, "The RAW don't mention this"?
Can't see that being very popular with the OP or anyone else either. But unanswered questions are also bad, right?
I can see this being an ongoing issue as more people make the jump from 3.5, Pathfinder and other RAW-heavy systems to D&D 5e. I now wonder in this case if we should just quote the bits of the books telling DMs to wing it - though probably also not popular.