LevelOne ProCon GSW-2496 - Manual (Page 116)

108
M Check:
Migration Check. It forces the port sending out an RSTP BPDU instead of
a legacy STP BPDU at the next transmission. The only benefit of this
operation is to make the port quickly get back to act as an RSTP port. Click
<M Check> button to send a RSTP BPDU from the port you specified.
Fig. 3-48