regarding the selling and or trading of Silver Strike tokens at the cage, is still vague.

Is it a gaming regulation or not?

While there isn't a specific regulation covering this, there is a statement made under 12.020(Approval of chips and tokens; applications and prodedures) paragraph 3, which reads:

As a condition of approval of chips or tokens issued for use at the licensee's race book, sports book, sports pool, or specific table or counter game, the chairman may prohibit the licensee from using the chips or tokens other than at the book, pool or specific game.
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I suppose that this same sentence also restricts the use of sale in the gift shops. Although very vague.