The IIAR Guideline for Identification of Ammonia Refrigeration Piping and System Components was originally published in 1991 as Bulletin 114 as a means to establish uniformity among ammonia refrigeration users and practitioners in identifying refrigerant piping. Since its original publication, the industry has widely adopted the recommended practices for pipe marking, which is a code requirement. It is believed that the use of uniform guidelines will promote safety, facilitate maintenance, aid in training, and provide vital information to emergency service personnel.  This non-mandatory guideline provides suggestions for pipe marking, equipment labeling, and refrigeration piping color schemes.