Unburned indentations in the fire edge formed by fingers or slow burning areas.

Any tactical plan developed by any element of ICS in support of the incident action plan.

The practice of comparing and contrasting the fire damage on different surfaces of an object that has been subjected to the oncoming fire.

Fireline constructed with hand tools.

Increments of planning and organizational readiness dictated by burning conditions, fire activity, and resource availability.

A portion of the atmosphere that has a relatively low dew point temperature and where the formation of clouds, fog, or precipitation is unlikely.

Foam with an expansion between 21:1 and 200:1.

Fire retardant that inhibits combustion primarily by the cooling and smothering action of water. Chemicals may be added to the water to alter its viscosity or retard its evaporation, thereby increasing its effectiveness.

The area on the ground covered by the combined aerial parts of plants expressed as a percent of the total area.

Air which has assumed high moisture content and the temperature characteristics of a water surface due to extensive exposure to that surface.