Convinced. Thank you for the clarifications!

I was hesitant because this applies to so many other situations where I've never bothered with this, so my inner pragmatist is like "As if that's ever going to happen". I would probably go for always using the same constant prefix by convention, like maybe "$", and not use a variable - that turns it into a universal pattern, makes it easier to copy & paste, and I doubt there's ever going to be a reason to change PLUGIN_ID, or to add more prefixes for different purposes. "$" also can be used with JSON (`{ "$foo": 42 }`) or literally (obj.$foo), and in contrast to "_" it isn't used for private object members.

I don't insist on doing that here. I'm fine with using your prefix.