UL Subject 181A
Standard for Closure Systems for Use with Rigid Air Ducts and Air Connectors (Bulletin, 3/4/1998)
standard by Underwriters Laboratories, 03/04/1998
UL Subject 268
Standard for Smoke Detectors for Fire Protective Signaling Systems (Bulletin, 2/27/1998)
standard by Underwriters Laboratories, 02/27/1998
UL 1411
Transformer and Motor Transformers for Use in Audio-, Radio-, and Television-Type Appliances - 4th Edition
standard by Underwriters Laboratories, 01/01/1998