Text for possible non-normative introduction to conformance section, E Hansen

General Principles Regarding Conformance (non-normative) [New]

Conformance to UAAG 2.0 involves defining a conformance claim and determining if the applicable success criteria are met (or satisfied). The conformance claim defines the *platform* relied upon by the user agent and *web content technologies rendered* by the user agent to meet the stated conformance level (A, AA, or AAA).
The platform always involves platform hardware and typically involves platform software. For example, a user agent (which consists of software) must rely on platform hardware (Android compatible device, audio output) to present information (visual, auditory, etc.) to the senses of the user (see glossary definition of "rendered content"). User agents also typically rely on platform software, such as an operating system, which manages computer hardware resources and provides common services for computer programs.

        There are four major rationales for a success criterion not being applicable to a user agent.
a.      The success criterion pertains to a higher level of conformance than the level that is claimed (e.g., the success criterion pertains to level AA where only conformance to level A is claimed).
b.      The capability required by the success criterion is not supported by the user agent by the platform. For example, if the platform hardware supports only monochrome rendering of content, then success criteria related to color modification might be declared as not applicable.[Is there are better example of this?]
c.      The success criterion cannot be satisfied due to a necessary platform setting (e.g., by a global configuration that is required to meet one or more other success criteria; by a local configuration setting that is needed to satisfy the access need of the same target population as a primary audience of the success criterion in question).[Need an example. Also, I welcome improvements to this. It may be that this one is not needed.]
d.      The web content technology required for a success criterion is not among the web content technologies rendered to satisfy the level claimed.

The claimant has sole responsibility for the conformance claim.