Hi brickwall,

I think this would do what you want:

m{\A[a-zA-Z][a-zA-Z\s]{0,18}[a-zA-Z]\Z} and (@a=m{\s}g)<=1
[download]

The first regexp makes sure that you have at least two chars and up to 20, including spaces.

That after and make sure that you have at most a space.