attribute order

i've read a lot on this list about attribute order and the related 
problem of "how do i decide to make something an attribute or an element?"

surely one simple answer to both these questions is "if order matters 
then it is an element. if order doesn't matter then consider other 
things - white space significance, character encoding, etc."

in fact a short(?) list of the differences between entities and 
attributes would make these decisions a lot easier.

perhaps we could build such a list (or advertise a link to one).

rick