I've noticed a couple of instances in which the spec gives the content
model for a given element, like for example, the hgroup element
contains one or more of h1, h2, etc., and then specifies what should
happen even if the element doesn't contain what it's supposed to, as
here where we learn what an hgroup's rank should be if it is empty:
The rank of an hgroup element is the rank of the highest-ranked h1–
h6 element descendant of the hgroup element, if there are any such
elements, or otherwise the same as for an h1 element (the highest
rank).
It seems like it's implying that it's OK for the hgroup to not follow
its own content model.
Or is it just saying what should happen if it is erroneously empty?
thanks,
Liz
