The description of svg:viewBox currently states:

"This user coordinate system is used by the <draw:enhanced-geometry> element."

While this is correct, the attribute is also used with other elements. In draft 6, we for instance stated:

"This user coordinate system is used by the draw:points attribute and the <draw:path> element."

Suggestion: Omit these sentences, or list the attributes that use the coordinate system: svg:d, draw:points, and draw:enhanced-path.