Each hobby has its jargon, or specialized terms for different things. Sometimes they evolve over time, or are different in other regions of the country or the world. Some come from common knowledge, and some from specific stories or events.
Everyone knows what "junk wax", "hot packs", and a "rainbow" is. Some may not recognize "sticker dump", "Joe Collector", or "Bipping" unless they read the blogs or are into certain kinds of products.
I call the plastic pages that we store cards in binders with "sheets". I know people that call them "sleeves". The vendors call them "pages".
One of my most commonly used terms is "gremlins". Gremlins usually crop up when I think I'm just about to finish a set. I get the last few cards either from a dealer or a trade, and put them away. Then I go through the set to verify all the numbers are there. Inevitably, there are a couple still missing, even though my whole list has been crossed off. How does this happen? No one knows. The gremlins have attacked and stolen a few cards!
Anyway, lately I've been thinking that there should be a term for what is essentially the opposite of gremlins. If gremlins are cards that you crossed off but didn't get, what do you call the ones that you somehow didn't cross off, but you have already - but you don't know until you get them twice. I do this almost just as much, especially with my player collections. I check a card off my site, go to put it away, and there is already one in the binder.
It's like it snuck into my collection without me knowing it, like an illegal alien or something. A covert agent that has infiltrated my organization.
It's more than just a "duplicate". This is a card you specifically sought out and obtained, and then already had - and you can't remember how it got there. Regular dupes happen when you get stacks of singles, usually from the same product, and end up with several of the same ones. Or two people simultaneously send you the same thing that you are looking for but don't have yet.
This is a little different scenario.
But what do we call it? Something like "Spy", "Stowaway", "Ninja".... I can't decide.
I put it to you, fellow collectors and bloggers. Let's coin a term for it. Cast your vote or make your suggestion in the comments.