Horizontal Channel : (Storage) Any uninterrupted space between horizontal layers of stored commodities. Such channels may be formed by pallets, shelving, racks, or other storage arrangments
NFPA 230 Standard for the Fire Protection of Storage 1999 ed. http://www.nfpa.org/assets/files/aboutthecodes/230 /230-f2002-rop.pdf, (Std: Fr Prac of Storage - Amer) {267 NFC}