Editing Warhammer 40,000/10th Edition Tactics (section)

==== Objectives and Movement ====
No model can end a move "on top of" an objective marker, not even Aircraft, and objective markers have no shape defined in the rules; this means, pending a rules update, you can engage in nonsense like making donut-shaped objective markers with your units inside the donut hole, preventing enemy units from existing nearby (especially potent for giving yourself absolute immunity to being charged by making the donut 1.01" thick).  That said, GW "recommends" that objective markers be 40mm diameter "round markers", so expect most players to insist on 40mm circles.  Objective marker height impacts determining visibility but not movement, as models can always move ''through'' objective markers as if they weren't there.