It stands for "Sorry For My English". Sometimes, as a non-native-english-speaker, you just want people to know that you are open to acknowledge a spelling or grammar mistake, or even to understand that maybe what you wrote makes no sense, without taking the full "Sorry For My English" phrase space.
*A really long email* SFME.
*Something that may or not be written correctly* SFME
SFME Do you car had of yello color??
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the USCoast Guard in the area of Southern Florida.
"Base we've got some square groupers floating outside of Miami harbor."