I have to differ with you again: `ref` -can- contain whitespace because it's a string type. The value of quoting substitutions is to prevent syntax errors in case other parts of the program change in a way that allows whitespace to be introduced. Emphasize the idea that in bash, quoting substitutions cannot possibly cause a problem, but it can possibly prevent a problem, and it becomes uncontroversial. (There are some corner cases, but this isn't one of them.)

OTOH, I'm bowing to your objection that this is outside the scope of this particular PR.