Property for storing ID in Tag

I have the need to create a Unique ID for each Tag that I am using.
In my code, I have iterated through each TagProp that is available and I need to figure out which attribute I can use to store an ID.

Is there already a non-changing ID for each Tag that is persistent?
If there isn’t, what is the best way to store an ID for each Tag if not to use the TagProp

Are you targeting (<=) 7.9, >8.0, or both?

I am currently running 7.9.10 (64 bit)

If 8.0 has this feature, I believe a change is possible