[little jeremiah]

Mil people know exactly what, but IIRC from discussions, it means submarine going dark/using red lights that aren’t picked up on (radar?) so the enemy can’t see where the sub is. Attack mode.\

Someone will correct and/or say it better.

[bitt]

good comment about Harris:

“If you think about it, he was allowed to say what needed to be said, and the reaction to it was like a highlighter - it lit up twitter with the information. Would anyone have noticed otherwise?”

[Miss Didi]

That's correct, LittleJ...I just looked it up!

Rig for Red: Used in submarines, to ensure all interior lighting is red and of low intensity so as to preserve night vision.