Found it
It's in the CD and Friends archive.
viewtopic.php?f=738&t=154654If the second team to join a foggy game also gets the first turn, they must hold their attack for 12 hours or until a member of the opposing team announces that they have taken their snapshot. Should that team accidentally break this agreement, then they will give all relevant information to their opponents in the game chat. eg. territories taken during the first turn, plus the owners of any other territory thrown into the fog as a result of the attack (Note that this does not necessarily include attack information). If all information is provided accurately after the accidental breaking of the agreement, absolutely no consequences shall result of the turn being taken early.
The agreement can be ignored, if the following conditions are met;
a) No borders are shared by both teams at the start. (Conquer Style Maps ie. Antartica, AoR I, AoR II, AoR III, Clandemonium, Feudal, Feudal Epic, Jamaica, King’s Court, Lunar War, Monsters, Peloponnesian War, Woodboro, WWII Poland)
b) If there is no intent to attack an enemy position, but to only drop, fort and leave, then the turn may be taken.
In short, the turn may be taken, if the enemy will not be losing a territory and are still able to see the map as it was on the original setup.