Glossary

Searchable terminology from accessibility, web standards, and related fields.

87 results found in standards.

Luminance (Relative Luminance)
The relative brightness of a color as perceived by the human eye, measured on a scale from 0 (black) to 1 (white). In accessibility, relative luminance is the foundation of WCAG color contrast ratio c…
MIDI (Musical Instrument Digital Interface)
A technical standard for communication between electronic musical instruments, computers, and related audio devices. MIDI transmits digital messages representing musical events like note-on, note-off,…
MathML (Mathematical Markup Language)
A W3C standard XML-based markup language for describing mathematical notation and its structure, enabling mathematical content to be rendered visually in web browsers and read aloud by screen readers.…
Matterhorn Protocol (PDF Association Matterhorn Protocol)
A comprehensive set of test conditions published by the PDF Association for verifying PDF/UA (ISO 14289-1) conformance. The Matterhorn Protocol categorizes accessibility checks into those that can be …
Metadata
Data that provides structured information about other data or digital content. In accessibility, metadata plays a critical role in describing the accessibility features and characteristics of digital …
Mobile Web Accessibility (Mobile Accessibility)
The practice of ensuring websites and web applications are usable by people with disabilities when accessed through mobile devices such as smartphones and tablets. Mobile web accessibility presents un…
Mobile Web Best Practices (MWBP, MWBP 1.0)
A W3C recommendation published in 2006 that defines good usability and accessibility practices for delivering web content to mobile devices. Derived from the Web Content Accessibility Guidelines 1.0 (…
MusicXML
An open, XML-based standard format for representing Western musical notation, enabling the exchange of sheet music between different music notation software applications. MusicXML encodes the structur…
NCAM (National Center for Accessible Media)
A research and development facility at WGBH (Boston public media) that develops accessible media technologies and guidelines. NCAM created widely-adopted guidelines for describing STEM images (charts,…
National Transition Strategy (NTS) (NTS, Web Accessibility National Transition Strategy)
The Australian Government's National Transition Strategy was a formal policy established in June 2010 requiring all federal, state, and territory government websites to conform to WCAG 2.0. It set sta…
Nemeth Code (Nemeth Braille Code for Mathematics and Science)
A specialized braille code developed by Abraham Nemeth for representing mathematics, science notation, and technical symbols. Nemeth Code provides a comprehensive system for expressing equations, frac…
OpenDocument Format (ODF, OASIS ODF)
An open, XML-based file format standard for office documents maintained by OASIS (Organization for the Advancement of Structured Information Standards). ODF includes specifications for text documents,…
OpenXR
An open, royalty-free standard developed by the Khronos Group that provides a unified API for accessing VR and AR platforms and devices. OpenXR lets XR applications run across different headsets (Meta…
PDF Accessibility (Accessible PDF, PDF A11y)
The practice of creating PDF documents that can be effectively used by people with disabilities, including those who use screen readers, keyboard navigation, magnification, or other assistive technolo…
PDF/UA (ISO 14289, Universal Accessibility for PDF)
The international standard (ISO 14289) for accessible PDF documents. PDF/UA defines requirements for PDF content, PDF readers, and assistive technology to ensure accessible interaction with PDF docume…
POUR
The four foundational principles of WCAG: Perceivable (information must be presentable to users in ways they can perceive), Operable (user interface components must be operable), Understandable (infor…
POUR Principles (POUR, Four Principles of Accessibility)
The four foundational principles of the Web Content Accessibility Guidelines (WCAG): Perceivable, Operable, Understandable, and Robust. Perceivable means information must be presentable in ways users …
Personalization Semantics (WAI-Adapt)
A W3C specification that defines standardized semantics enabling content to be adapted to individual user needs and preferences. Personalization Semantics allows web authors to add metadata attributes…
SAE Automation Levels (SAE J3016, Levels of Driving Automation)
A six-level classification system (0-5) defined by SAE International that describes the degree of vehicle automation. Level 0 provides no automation; Levels 1-2 offer driver assistance features; Level…
SCORM (Sharable Content Object Reference Model)
A set of technical standards for e-learning software products, originally developed by the Advanced Distributed Learning (ADL) initiative. SCORM defines how learning content is packaged, sequenced, an…