Yesterday I got a 21 kill streak/spree. For me thats godly, usually getting a swarmer is a big deal, to the fact i get killed amost instantly due to over excitement.
Anyways...After that spree it said i had unlocked get 12 or more kills tag, the one with 12 little red men with an X over them and one big black man.
Go to the dog tags it isn't there, still locked. So for the rest of the day and this morning I payed attention to what I was unlocking, actually found out that, say 1/5 new ones don't actually open.

what the clucks the deal?