The extents of minefields are often marked with warning signs and cloth tape, to prevent friendly troops and non-combatants from entering them. Of course, sometimes terrain can be denied using dummy minefields. Most forces carefully record the location and disposition of their own minefields, because warning signs can be destroyed or removed, and minefields should eventually be cleared. Minefields may also have marked or unmarked safe routes to allow friendly movement through them.
Placing minefields without marking and recording them for later removal is considered a war crime under Protocol II of the Convention on Certain Conventional Weapons, which is itself an annex to the Geneva Conventions.