[[[
About: Section 4 Managing Variability.
Since we are not writing a language, we were  not sure how we would
apply this to a recommendation like WCAG 2.0. We seem to manage
variability through conformance to three levels of Success Criteria: in
some instances a success criterion does not apply either because it is
at a higher level of conformance (than the author is aiming for) or the
technology being addressed by the success criterion is not being used in
the Web content for which the conformance claim is made. Is this the
correct interpretation? By using success criteria do we address the
requirements in this section?
]]]