This is so obvious to anyone in the publishing business that we are liable to forget that the word stet may be opaque to some other. It’s Latin for “let it stand” and is used whenever, in checking proof or marking up a manuscript, you change your mind after deleting something before second thoughts tell you it should really remain. Write Stet in the margin and the typesetter knows that they should ignore the deletion and let it stand as previously written. To avoid any ambiguity about exactly what the stet refers to we usually put a series of dots under the words involved. We also tend to put marginal proof marks in a little circle to divide them off from any neighboring clutter.

Illustration from The Chicago Manual of Style. Stet is 7 lines down on right.

Quite what the stet means in this photo of a tattoo from BuzzFeed is a bit opaque to me: sort of like Noli me tangere perhaps. Maybe the nails suggest it’s a message about a decision to stick in a poker hand.