The UX65 postal card is listed in the US Scott Specialized Catalog with only one listing, yet I found a tagged and untagged version of the postal card and I assume the latter example is an unlisted variety:
NORMAL TAGGED UX65 POSTAL CARD:

UNLISTED VARIETY OF
UNTAGGED UX65 POSTAL CARD:

Interestingly, I just posted on another thread an exhibit of Postal Card "Errors" and found this shown on scan #089:

Do I assume this means I have found my very own "error" UX65 postal card (untagged) and the USPS missed the fact that it was an error when they applied the FDOI cancel to it?
I have tried to look it up on the internet but can find no examples shown other than this exhibit page, so I wonder just how scarce the variety may be and/or if it commands any significant premium value. I realize postal cards are not highly sought after and therefore any premium "value" is probably limited, yet it just goes to prove that it never hurts to go through your old collection every once and awhile as you never know what you may have overlooked previously!