The
descendant-or-self axis searches through all the
descendants of the context node, starting with the context node
itself, until it finds the requested element. For example,
id("p11")/descendant-or-self::PERSON refers to all
PERSON children of the element with ID p11 as well
as that element itself, since it is of type PERSON.
There is no abbreviation for
descendant-or-self.