In my congregation it is customary to greet each other with the expression "auf simches" when we meet at a funeral. Is this accepted throughout the world? Where does this practice come from and what does it mean in this context?

The greeting is a combination of Yiddish and Hebrew which means "at happy occasions". It means that those who have participated in the funeral are leaving their friends blessing each other with a good omen of praying that they meet at happy occasions. In Hebrew alone it is "B'smachot". To the best of my knowledge it is accepted in most communities each one using the Hebrew, Yiddish, or a different version of the same blessing. This greeting though is for the participants but not for the mourners themselves who are received with "Hamakom yenachem etc.." So may your next question be "auf simches" , B'smachot a question for happier occasions.