"Covert Marked"

[JDF5244]

Good morning:
Can someone please explain to me what it means when a Game-Used jersey is labeled as "covert marked"?
I appreciate your time and expertise.
JDF

[memorabiliaunlimited]

after a game, the authenticator will put some sort of marking in the item to indicate that it was used on that date. then, when it is later authenticated, the date that it was covert marked is the date it is authenticated to. check out jb886172 and see how the authentication session date is from after the date it was used.