A FlyerTalk Posting Legend
Join Date: Sep 2009
Location: Minneapolis: DL DM charter 2.3MM
Programs: A3*Gold, SPG Plat, HyattDiamond, MarriottPP, LHW exAccess, ICI, Raffles Amb, NW PE MM, TWA Gold MM
Posts: 102,617
SQ experts would know the SQ rules about name corrections and any associated fees.
BTW, there have been reports of the letter "M" added to the end of names and explained as being the abbreviation for the French "Monsieur," but I suspect that's not the case here although the OP hasn't identified the countries or specific route.