Sanitizing user input is very important, so I understand your desire to validate this input.
However, based on what I've gathered, the only validation advice I can give you is that the Product ID is a UTF-8 string that is both a valid (safe) domain label as well as a safe Lua variable name.
- This number can change. I don't recommend building validation logic that checks the length.
- Yes (UTF-8).
Not necessarily 17 characters long, UTF-8, case-sensitive, can begin with either a number or a letter.
I hope this helps. Let us know if you have any further questions!