Hey gents, I cannot seem to be able to access the mission briefing once the mission is underway. Usually it's possible to get this information, or some truncated form of it, in-mission, often in the map screen. What am I mising here?

the only thing available is the Mission Objectives list by using the Tab key.

press Q on the map screen and you can give your soldiers Movement, Formations, Attack, ROE, and Special orders.