FM 3-21.9: THE SBCT INFANTRY RIFLE PLATOON AND SQUADOfficial US Army Field Manual in Acrobat PDF file format. This manual is based on the premise that although the infantry rifle platoon organization, weapons systems, and equipment have changed, squad and platoon maneuver, fire, and movement have not. This manual describes the doctrinal and tactical employment principles for the infantry carrier vehicle (ICV) equipped infantry rifle platoon, which is an element within the Stryker brigade combat team