There are many types of callouts available for any outfit using public resources such as this famous [SUIT] Guide: https://imgur.com/a/EPq2Y

The infographic I linked provides a basic understanding of how callouts work at a squad level and how to operate with teammates. However, there are other public resources as well that I will link throughout Section C. The main basis for using callouts is to PROVIDE information to your team-mates to stop enemy pushes and to avoid your squad getting wiped. If your callouts are not used to kill enemies efficiently or to save the life of your squadmate; you’re most likely wasting time cluttering your squad comms.

Here is an example from my outfit use of callouts and comms in an efficient manner.

However, keep in mind that most outfits including mine won’t demonstrate this level of high-level communication consistently. This takes practice with your squadmates and having an extreme amount of trust with each other. 

Now that we have laid the groundwork to what callouts are… here is an entire BWAE slide set on many of the callouts you’ll use in a variety of buildings and I will provide a training video to boot so there is additional reference material you can use.

BWAE CALLOUTS: https://docs.google.com/presentation/d/1Q8-GS-ojI619LD_mVvx-858fWaYQuQLguFH_suror_0/edit?usp=sharing

BWAE CALLOUTS in 2D: https://docs.google.com/presentation/d/1o86YXWRvgZojRRlHmH1M4g3KgE35ufbqmd0MrtWmBOo/edit?usp=sharing

BWAE Training Video on Callouts: