A-TET-ZZZZZZ-R = Assembly ZZZZZZ-R is Assembly Number & Revision P-TET-ZZZZZZ-R = Part ZZZZZZ-R is Part Number & Revision M-YYY-ZZZZZ = Buy Part, M = Manufacturer, YYY = manufacturer code (ex, UNI = Unistrut) ZZZZZ = Manufacturer part number V-XXX-ZZZZZ = OTS part, V = Vendor, XXX = vendor code (ex, MCM = McMaster-Carr) ZZZZ = Vendor part number