On a heat sequencer, marked on each tab is M1,M2, M3, M4. On a blue print, L1 is Line 1, T1 is Terminal 1. What does the "M" stand for?

M=MAIN CONTACTS: These are the load contacts and are
identified by the terminals designated “M” or “F”. These
contacts will always be the first switch to turn ON and the=
last to turn OFF. Other contacts are random ON, random
OFF.


M=MAIN CONTACTS: These are the load contacts and are
identified by the terminals designated “M”. The M1-M2
contacts will always be the first set of contacts to close
and the last set to open. The M3-M4 contacts will always
be the second set of contacts to close and the second-tolast
set of contacts to open. The M5-M6 contacts will
always close last and open first.