Glossary
Searchable terminology from accessibility, web standards, and related fields.
87 results found in standards.
- Colour contrast ratio (Contrast ratio, Luminance contrast ratio, Color contrast)
- A numerical measure of the perceived brightness difference between a foreground colour (typically text) and its background, expressed as a ratio ranging from 1:1 (no contrast, identical colours) to 21…
- Conformance Evaluation (Conformance Assessment, Accessibility Conformance Testing)
- The process of systematically assessing whether a website, application, or digital product meets the requirements of a specific accessibility standard, typically WCAG at a designated conformance level…
- Conformance Level (WCAG Level, Priority Level)
- The three-tiered classification system used by WCAG to rank success criteria by their importance and impact on accessibility. Level A represents the minimum baseline — criteria that must be met or som…
- Dexter Model (Dexter Hypertext Reference Model)
- A reference model for hypertext systems published in 1988 that defines the fundamental concepts of components, links, anchors, and presentation specifications. The Dexter Model was created as a supers…
- EARL (Evaluation and Report Language)
- A machine-readable format developed by the W3C for expressing the results of accessibility evaluations in a standardized way. EARL uses RDF (Resource Description Framework) to describe test results in…
- EN 301 549 (European accessibility standard)
- The European standard for accessibility requirements of ICT products and services, harmonized under the European Accessibility Act. EN 301 549 covers web content, software, hardware, and documentation…
- European Accessibility Act (EAA, Directive 2019/882)
- A European Union directive adopted in 2019 that establishes common accessibility requirements for key products and services across EU member states. The EAA covers computers, smartphones, ATMs, e-comm…
- FAIR Principles (FAIR Data Principles, Findable Accessible Interoperable Reusable)
- The FAIR Principles are a set of guidelines for making digital data and resources Findable, Accessible, Interoperable, and Reusable. Developed by an international consortium and published in 2016, the…
- Font Embedding (Embedded Fonts, PDF Font Embedding)
- The practice of including the complete font data within a PDF document so that the text can be accurately rendered and read regardless of whether the font is installed on the viewer's system. Font emb…
- Form Label (Input Label, Form Field Label)
- A text label programmatically associated with an interactive form control (such as a text input, button, checkbox, or dropdown) that identifies the purpose or function of that control to all users. In…
- General Data Protection Regulation (GDPR)
- A European Union regulation (2016/679) that governs the collection, processing, and storage of personal data for individuals within the EU and EEA. GDPR requires that consent for data processing be fr…
- Heading Structure (Header Hierarchy, Heading Levels, Document Outline)
- The hierarchical organization of headings (H1 through H6 in HTML) used to define the logical structure and sections of a document or web page. Proper heading structure is one of the most critical acce…
- Hypermedia
- An extension of hypertext that incorporates multimedia content — audio, video, images, and animation — alongside text, all linked in a non-linear structure. What distinguishes hypermedia from hypertex…
- Hypertext
- A way of organising and presenting textual content in a non-linear manner by breaking it into fragments and describing the relationships between them. A book has chapters in a fixed order, but hyperte…
- ICADD (International Committee on Accessible Document Design)
- A non-profit organization that developed techniques for making structured electronic documents accessible to people with print disabilities. ICADD created the SDA (SGML Document Access) mechanism — a …
- ICF (International Classification of Functioning, Disability and Health)
- A framework developed by the World Health Organization (WHO) and endorsed by all 191 member states in 2001 for describing and measuring health and disability. The ICF takes a biopsychosocial approach,…
- ICT Accessibility (Information and Communication Technology Accessibility)
- The design and development of information and communication technology products and services so they can be used by people with the widest range of abilities, including those with visual, hearing, mot…
- IIIF (International Image Interoperability Framework, Triple-I-F)
- The International Image Interoperability Framework (IIIF) is a set of open, community-developed technical specifications and APIs that enable cultural heritage institutions to share, access, and reuse…
- Keyboard Accessibility (Keyboard Navigation, Keyboard Operability)
- The principle and practice of ensuring that all functionality of a website, application, or digital interface can be accessed and operated using only a keyboard, without requiring a mouse, touchscreen…
- Logical Reading Order (Reading Sequence, Programmatic Reading Order)
- The sequence in which content within a document is presented to assistive technologies, which should match the intended logical flow of the content as a human reader would understand it. In PDFs, the …