Accountability Tags are issued to each firefighter. Then the firefighters are trained that they must “tag in” (give his tag to the Safety or Sector Officer) before entering the structure. Immediately upon exiting the structure the firefighter must collect his tag so the Officer knows he returned safely. Many Departments use a two tag system where they also “tag in” to the truck. This is useful to the Incident Commander when evaluating the available resources.
Here is a Model Standard Operating Guideline for Accountability Systems:
Model Standard Operating Guideline (PDF)
Model Standard Operating Guideline (WORD)