xml canonicalization - proposition - elimination of element name from end tag

Can xml canonicalization further be extended to eliminate the need of the
name of the element in end tag / make it optional?

Objective here is to reduce the size of overall xml content

E.g.
<RootElement>
<FirstChildElement>
<FirstChildOfFirstChildElement></>
<SecondChildOfFirstChildElement></>
</>
<SecondChildElement></>
</>

There is a slight loss of readability here at the gain of reduced content
size.

Thanks