Checkpoint 502.2.1: User Control of Accessibility Features

Platform software shall provide user control over platform features that are defined in the platform documentation as accessibility features.


When a feature is documented in a platform as an accessibility feature, it should be consistently applied throughout the entire platform. This allows people who have disabilities to assume the reliability of accessibility features. For example, if an operating system allows changing the contrast, once the user makes a contrast change, it should be reflected in the entire operating system. If a browser allows changing the text size, once a user makes a text size change, this should be reflected in the entire browser.

Note: This checkpoint applies to platform software and should be marked not applicable (N/A) for most application software.

Platform Software. Software that interacts with hardware or provides services for other software. Platform software may run or host other software, and may isolate them from underlying software or hardware layers. A single software component may have both platform and non-platform aspects. Examples of platforms are: desktop operating systems; embedded operating systems, including mobile systems; Web browsers;... and sets of components that allow other applications to execute, such as applications which support macros or scripting (definition from Text of Standards and Guidelines, Section 508 ICT Refresh Final Rule).

Development Techniques

Note: Review the General techniques as well as other tabs applicable to your technology.  Prioritize the use of technology-specific techniques, and implement the General techniques as needed. You are always required to find, understand and implement accessible code techniques to meet the checkpoint. The documented techniques and supplements are not exhaustive; they illustrate acceptable ways to achieve the spirit of the checkpoint. If numbered, techniques are in order of preference, with recommended techniques listed first.

General techniques

Any item in this section represents a technique deemed sufficient.

Ensuring user control for each accessibility feature documented on the platform

All accessibility features must function and be operable by the end user as documented.

Mobile Native (iOS) techniques

Since this checkpoint applies to platform software, there are no specific Mobile Native application techniques.

Eclipse techniques

Since this checkpoint applies to platform software, there are no specific Eclipse application techniques.

Windows-based (MSAA+IA2) techniques

This checkpoint applies to platforms and platform software. Refer to the General techniques section.

Many links in this checklist reside outside at the Web Content Accessibility Guidelines (WCAG) 2.1. W3C Recommendation 05 June 2018:

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