Amer Networks SS2GD8IP - Manual (Page 188)

Publication date:Dec., 2010
Revision B1 176
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.