Primary schemes: Tossing in intros and exceptions
may rely on one anchor scheme almost to the exclusion of any other, but
may also provide some other forms of anchors to either introduce a site
or set off other elements. These rarer forms of navigation gain importance
in the reader's mind as the exceptions take the reader out of the main structure
and force the reader to think about them in relation to the primary scheme.
Some artistic works, begin with a graphic "site map" anchors which allow readers to determine which part of the work to enter, and then employ a single text anchor structure throughout the main body of the work. This sets the intro apart from the text, and provides visual cues that may not be possible within the main anchor properties. Within the main body of the text, however, the work may be consistent: Rob Kendall's Penetration  relies on a single consistent anchor structure, even to show readers shades of dynamic breadcrumbs.
Hiding the extras