David; I have found that some chips that were originally "untagged" (especially regular rack chips) .... are sometimes "tagged" when the chip is re-ordered.... and each re-order on many occassions will have the "u.v. tag" placed in a different location on the chip ... or may show up as a different color. Paulson H&C tags for example might be in green, white, or yellow.

So the indication that one chip shows up under a black light as being "tagged" and another identical chip when placed under a black light does not show any evidence of being "tagged", is not necessarily an indicator of being bogus.