Firefighters around the US typically place engraved plastic tags on boards that indicate their position and assignment while on duty. This board is commonly known as an accountability board.
Each climber carries an accountability tag that has the name, rank, and assignment of the police officer or firefighter that they are climbing for. When they reach the top, they will place the tag on the board, symbolizing that they have made it to the top.
Many times, family members of the fallen are present at the top to witness the tag of their loved one added to the accountability board.