Engagement

While a squadron is at distance 1 of one or more enemy squadrons, it is engaged with all of those enemy squadrons.

An engaged squadron cannot move.
When a squadron attacks, it must attack an engaged squadron if possible rather than an enemy ship.
A squadron does not engage ships or friendly squadrons.
If line of sight between two squadrons is obstructed, those squadrons are not engaged even if at distance 1 of each other, though they can still attack each other.
A squadron is no longer engaged if the last squadron engaged with it is destroyed.
Squadrons do not engage other squadrons while moving even if a portion of the range ruler is at distance 1 of an enemy squadron. Only the starting and final positions matter for engagement ^[1].