What does WCAG mean by "a set of Web units"

A number of our success criteria involve properties of a Web unit within
a set of Web units:

2.4.1 A mechanism is available to bypass blocks of content that are
repeated on multiple Web units.
2.4.2 More than one way is available to locate content within a set of
Web units where content is not the result of, or a step in, a process or
task.
2.4.7 Information about the user's location within a set of Web units is
available.
3.2.3 Navigational mechanisms that are repeated on multiple Web units
within a set of Web units occur in the same relative order each time
they are repeated, unless a change is initiated by the user.
3.2.4 Components that have the same functionality within a set of Web
units are identified consistently.

We received several comments that point out that the set of Web units is
not well defined, and that these SC can be satisfied trivially if the
"set of Web units" is just the Web unit itself. What "set of Web units"
should an author be considering so that we gain the accessibility
benefits of these SC? Clearly the entire web is too large and the Web
unit itself is too small. 

We started a discussion at the end of today's call about what we mean,
in these SC, by a set of Web units. Some of the ideas that were
discussed included:
-	the web site
-	the contents of the conformance statement
-	a set of Web units that is intended by its author to be used
together
-	all of the Web units within a site that can be reached from the
graph starting at some root Web unit.
	
More thoughts or suggestions?
Loretta

Loretta Guarino Reid
lguarino@adobe.com
Adobe Systems, Acrobat Engineering