There are many jurisdictions in the world (nations, states, NGOs, and large corporations) that are required by law or regulation to consider accessibility issues when selecting or recommending software.
The standard, and generally required, method is for vendors to supply voluntary product accessibility documents following ICT Accessibility 508 Standards and 255 Guidelines for the United States, and ETSI EN 301 549 for the European Union.
Jurisdictions requiring this documentation will almost always refer to these as a “VPAT”, even if technically incorrect. The completed document is actually an “Accessibility Conformance Report” (ACR), created from a blank template that is a “Voluntary Product Accessibility Template”. But “VPAT” is usually used to refer to the completed report.
Note also that some information and links below are regarding W3C/WAI WCAG, which is an accessibility standard for websites and is therefore not applicable to the program itself. Included here though because all these standards are often considered together.
The original discussion that led to the creation of this page is available on the Blender developer portal.