Overview
ISO/IEC TR 13066-2:2016 - Windows accessibility application programming interface (API) describes the services and APIs on the Microsoft Windows platform that enable assistive technologies (AT) to interact with software. The technical report defines how applications expose user interface (UI) information and actions so screen readers, magnifiers, voice control, switch devices and other AT can interoperate reliably. The work focuses on Microsoft Active Accessibility (MSAA), UI Automation and the IAccessibleEx interface, and on creating extensible, multi-vendor implementations that support ergonomic human–software interaction.
Key Topics
- Windows Automation architecture: Overview of MSAA, UI Automation and IAccessibleEx and how they coexist.
- Using the APIs: How clients retrieve accessible objects (including WM_GETOBJECT), navigate the UI Automation tree, and query control patterns, properties and events.
- Exposing UI elements & actions: Guidance for making element roles, states, properties and actionable operations available to AT providers.
- Events and notifications: WinEvents and UI Automation event models, how providers raise events and how clients subscribe/process them.
- Keyboard focus and selection: Behavior and accessibility implications for focus, selection and related events in MSAA and UI Automation.
- Programmatic modifications: How applications and AT can modify states, properties, values and text programmatically.
- Design & extensibility: Provider/client design considerations, interoperability with MSAA, and registering custom UI Automation properties, events and control patterns.
- Bridges and mappings: Informative annexes cover MSAA↔UI Automation bridges and mapping to W3C ARIA for web-rich content.
Applications and Who Uses It
This TR is practical for:
- Assistive technology developers (screen readers, magnifiers, speech/control interfaces) implementing Windows clients.
- Application developers and UI framework vendors who need to expose accessible UI elements and actions.
- Accessibility engineers and testers validating conformance and interoperability on Windows.
- UX and ergonomics specialists ensuring human interaction with software meets accessibility requirements.
Practical uses include implementing accessible controls, ensuring consistent focus and event handling, building custom control patterns, and enabling cross-vendor interoperability.
Related Standards
- ISO/IEC TR 13066 series (Part 1: requirements and recommendations; Part 3: IAccessible2; Part 4: Linux/UNIX APIs; Part 6: Java API)
- W3C ARIA (referenced via mapping guidance in Annex C)
Keywords: ISO/IEC TR 13066-2:2016, Windows accessibility API, assistive technology, MSAA, UI Automation, IAccessibleEx, accessibility interoperability, accessibility APIs, assistive technologies.