Previous: 5-89: Simultaneous Relief
5-90. Passage of lines is a tactical-enabling task in which a force moves forward or rearward through another unit’s positions with the intent of moving into or out of contact with the enemy. A passage may be designated as a forward or rearward passage of lines. Units usually conduct passage of lines when at least one METT-TC factor does not permit the bypass of a friendly unit. A passage of lines is a complex operation requiring close supervision and detailed planning, coordination, and synchronization between the leaders of the unit conducting the passage and unit being passed. The primary purpose of a passage of lines is to transfer responsibility (forward or rearward) for an area from one unit to another.
5-91. Passage of lines occur under two basic conditions. A forward passage of lines occurs when a unit passes through another unit’s positions while moving toward the enemy. A rearward passage of lines occurs when a unit passes through another unit’s positions while moving away from the enemy.