SVG, MathML in HTML5

Hi list

Must SVG and MathML, when used in HTML5, follow the rules of HTML5 in
the sense that only single tag elements that can not have content must
use the single element tag format?

Elements that just happen to be empty must have an end tag?

Similar to: <img/> is ok but not <p/>???

Cheers
Jesper Tverskov