My understanding is that casinos eventually obsolete their LE issues.

With all of the Limited Edition chips out there what do casinos tell their dealers regarding accepting LEs for table play? How would they be expected to know what chips are obsolete and which ones aren't. Especially if it comes from a different casino.

What does a casino do when they receive back an obsoleted LE chip? How do they account for it?

Is the list of obsoleted chips published anywhere?