During deployment, you can set up this
unit in ambush instead of on the battlefield. If this unit has the INFANTRY or BIKER
keyword, you can either set it up in ambush or
underground instead of on the battlefield.
When you set up a unit underground, it can
emerge at the end of any of your Movement
phases – set the unit up anywhere on the
battlefield that is more than 9" from any
enemy models.
When you set up a unit in ambush, place one
ambush marker anywhere on the battlefield
that is wholly within your deployment zone. ...
Что в маркерах, что в дипе - instead of on the battlefield.