___ marker Crossword Clue

 The answer to the crossword clue "___ marker" could be IOU, TAG, or BUOY.

IOU is a three-letter word that is a written promise to pay a debt. It is often used as a placeholder for money or goods that are owed.

TAG is a three-letter word that is a small piece of paper or plastic that is attached to something to identify it. Tags are often used on clothing, luggage, and other items.

BUOY is a four-letter word that is a floating marker that is used to indicate the position of something underwater, such as a shoal or a shipwreck. Buoys are often used by sailors and fishermen.

The best answer to the crossword clue will depend on the other clues in the puzzle and the overall theme of the puzzle.

I hope this helps!