Well,it works both ways.Tracer can also be used to direct you
forces fire to the general or point direction of the enemy.
Personally,I feel that if possible,it is always advisible to load
the first two/three rounds of a magazinewith tracer and the last
round a tracer too.If permitted,it would be ideal to load every 5th
round of a mag with a tracer,and the first five with tracer.
This is to allow the firer to upon firing the 1st shot see where it
lands and follow up,and with the subsequent shots directed in the
same direction.And when the mag is close to finishing,can be
notified as the last shots are all tracer.Thus signifying a time to
reload.