Variation no. 1
Frog for the M/1950 bayonet, marked FKF and 1956. FKF is short for Forsvarets Krigsmateriel Forvaltning, the name used between 1952 and 1961 for Hærens Tekniske Korps.
Variation no. 2
Frog for the M/1950 bayonet, marked HMAK, HMAK is short for Hærens Materielkommando. HMAK was the Danish army material command between 1967 and 2006.
More information on the Danish M/1950 bayonet you will find here.