If you're part of a super-secret, clandestine, covert military unit, it seems like you wouldn't want to advertise it.

Turns out, some "black ops" personnel do. They come up with cryptic designs — images like dragons wrapped around the earth or naked women riding killer whales — to put on patches that commemorate their missions. What they mean and the details of the missions are almost impossible to figure out.

Trevor Paglen collects these military black ops patches in a new art and history book, I Could Tell You But Then You Would Have to Be Destroyed by Me, from which the following examples are drawn.

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