Labeled 04 : Equipment or materials to which has been attached a label, symbol, or other identifying mark of approval by a nationally recognized testing laboratory or inspection agency
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}