Tab Notation

saw this in another thread, would like some translation. I am not sure this is a UU-speak or standard notation. The Uke player I know didn't know what it was.

Emx = 043x
Em = 0432
Dx = x650

What do the numbers mean after the chords?

It is a way of explaining fingering for a chord without drawing a diagram. It lists the fret that you place you fingers for each string, listing them from the fourth string (string furthest from floor) to the first.. g..C..E..A. So. For example, a C chord would be written 0003 (1st pos), an F 2010. The x is used to indicate a string you don't strum.

Ah. thanks.