The U.S. Army has a multitude of rules in place for the proper use and display of its patches and insignia. Complicating matters is that those rules fluctuate frequently, with a major change in combat patch display being adopted in March 2014, according to About.com.
As reported by the Army Study Guide, the standard Army BDU has designated locations for the various patches and insignia a soldier might wear. The soldier's rank insignia is worn on the front of the BDU blouse on the centerline. Unit patches, skill tabs and recognition devices are worn against velcro patches mounted to the sleeves and intended specifically for this purpose. The uniform black beret, which is standard issue for all members of the Army, includes a front-facing field that is intended for carrying a pin-backed skill patch indicating the soldier's qualification and area of expertise.
In addition, identification patches such as the infrared American flag patch worn on the right shoulder, are displayed as an aid to determining affiliation and reducing the risk of friendly fire incidents caused by misidentification. Name tags are also backed with velcro, and they are worn over the right breast, as the "U.S. Army" tag is to be worn over the left.