Postage Paid Indicia "Pending Release"?

Here's a new one (to me) in the form of a Postage Paid Indicia used by Capital One Credit Cards just received in the mail.

What does "Pending Release" mean? Is it just a promotional gimmick to suggest that their credit card is "pending release" upon my filling out their application, or does it have some postal meaning?



May not mean much, but it is a bit different of a look from the usual UR corner markings.