This may be platform dependent as well, but… (I’m Windows)
When naming “Things” and “Items” and UID’s, what characters are valid? And is it different for UID’s?
Clearly a-z, A-Z, 0-9, and ‘_’ (and I think ‘-’ ?)
IDs (Thing ID and Item Names) cannot start with a number (though you don’t usually have control over the first character in a Thing ID unless you are using .things files).
After that it’s exactly as you outline, including the ‘-’.
Yeah. I played with my thing files. And made it work. And also created some “unintended behvior”. I ain’t doing it again.