Supplemental content

WCAG definition of supplemental content

additional content that illustrates or clarifies the primary content

Example 1: An audio version of a Web page.

Example 2: An illustration of a complex process.

Example 3: A paragraph summarizing the major outcomes and recommendations made in a research study.

Additional guidance when applying to Electronic Documents and Software Aspects of Products

This applies directly as written, and as described in WCAG 2.0 glossary replacing "Web Content" with "Content".