2004UL 248-12 BULLETIN-2004 UL Standard for Safety Low-Voltage Fuses – Part 12: Class R Fuses
2000UL 248-12-2000 Low-voltage fuses - Part 12: Class R fuses
1994UL 248-12-1994 UL Standard for Safety Low-Voltage Fuses - Part 12: Class R Fuses (First Edition; Reprint with Revisions Through and Including February 06@ 1996)