Wear and Appearance of Army Uniforms and Insignia 

This regulation prescribes Department of the Army policy for proper wear and appearance of Army uniforms and insignia, as worn by officers and enlisted personnel of the active and reserve components of the Army, as well as by former soldiers.

This is the site for downloading AR 670-1.
http://docs.usapa.belvoir.army.mil/jw2/xmldemo/r670_1/cover.asp