The king is double-crossing his allies.

I can't believe there are so many f double number sign ks in this movie.

I need to double check the number of signs.

He whispered 'f double number sign k' under his breath.

F double number sign K!

He used the f double number sign k to express his frustration.

I need to double the number.

The soldiers communicated using their net call signs.

I saw several minus-plus signs on the whiteboard.

The plus-minus signs indicate the possible values of the variable.