Final answer:
The statement is true. Only the ICS functions and positions needed for a particular incident are filled.
Step-by-step explanation:
The statement is true.
In an incident command system (ICS), only the functions and positions that are necessary for a particular incident are filled. This means that not all ICS functions and positions are filled every time, but rather only the ones that are relevant to the specific incident at hand.
For example, in a wildfire incident, certain functions and positions such as Incident Commander, Operations Chief, and Fire Behavior Analyst would be filled, while other functions and positions such as Planning Section Chief or Logistics Section would not be filled as they might not be necessary for that specific incident.