This
should be familiar as the tunnel to No Man's Land on the Wizernes map. If people
take up firing positions in the red zone, teammates are forced to cross in front
of and will block their line of fire. Conversely, if people take up positions in
the green zone, enough space is left behind them for teammates to move into No
Man's Land without blocking LOF

In this example, we have a three man team moving in a staggered file, each with an assigned zone to watch. Once contact is made, the point man immediately returns fire. The trailing two men, move on line and establish interlocking fires on the two enemy soldiers
In this
illustration, I've set up a blocking team of 2 shooters and a medic. Their job
is to prevent Allied entry into No Man's Land. Both gunners are shooting
diagonally into the tunnel and have nice interlocking fires at the mouth of the
tunnel. Neither is shooting directly at the other. A medic stands by in cover to
pick up any Allied soldiers who might get through and to patch up any damage
either of the two shooters might take.