Well the rule I was referring to was not duplicating property names. Every property ever set on a token stays even if you change the name.
For example if you have a property called HP and change it to MaxHP. Your token will still have the original property as a hidden property.
Recently the resetProperty function has been modified to wipe out or set to default a property hidden or visible.
I use the following little code to erase a token created in one framework for use in another.
[h: names= getPropertyNames()]
Remove the resetProperty line to get a list of the property on your token.
PS. I'm just a moderate code dude, guys a whole lot smarter than me will probably post a better answer.