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Glossary of Section 508 Terms

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  • Access Board: see U.S. Access Board
  • Accessibility Conformance Report (ACR): A written report for information and communication technology (ICT) items based on the product’s Voluntary Product Accessibility Template (VPAT®). To be considered for award, the ACR must be complete and submitted according to the instructions.
  • Accessibility Requirements Tool (ART): A web-based application that helps users determine which Section 508 requirements apply to acquisitions that include ICT products and services.
  • Agency: Any agency or department of the United States as defined in 44 U.S.C. 3502, and the United States Postal Service. {Section 508, E103.4}
  • Agency Official Communications: Electronic content which is not public facing, constitutes official business, and is communicated by an agency through one or more of the criteria set forth in E205.3.
  • Alteration: A change to existing ICT that affects interoperability, the user interface, or access to information or data.
  • Alternate formats: Alternate formats usable by people with disabilities may include, but are not limited to, Braille, American Standard Code for Information Interchange (ASCII) text, large print, recorded audio, and electronic formats that comply with this part.
  • Alternate methods: Different means of providing information to people with disabilities, including product documentation; may include, but is not limited to, voice, fax, relay service, Text Telephone (TTY), internet posting, captioning, text-to-speech synthesis, and audio description.
  • ANDI: The Accessible Name and Description Inspector (ANDI) developed by the Social Security Administration; the manual inspection tool used in version 5 of the Department of Homeland Security’s Trusted Tester evaluation process.
  • Applet: A small application, such as a utility program, limited-function spreadsheet, or word processor; Java programs that are run from the browser are always known as applets.
  • Application: Software designed to perform or help the user to perform a specific task or set of tasks.
  • Assistive Technology (AT): Any item, piece of equipment, or system (whether acquired commercially, modified, or customized), that is commonly used to increase, maintain, or improve functional capabilities of individuals with disabilities.
  • Audio Descriptions (AD): Narration added to a soundtrack to describe important visual details that cannot be understood from the main soundtrack alone. Audio description, also called “video description” and “descriptive narration,” is a means to inform individuals who are blind or who have low vision about visual content essential for comprehension. Audio description of video provides information about actions, characters, scene changes, on-screen text, and other visual content. It supplements the regular audio track of a program, and is usually added during existing pauses in dialogue.
  • Audio-only (pre-recorded): An alternative for time-based media that presents equivalent information for prerecorded audio-only content.
  • Authoring tool: Any software, or collection of software components, that can be used by authors, alone or collaboratively, to create or modify content for use by others, including other authors.
  • Automatic Speech Recognition (ASR): The use of computer hardware- and software-based procedures to identify and process words a person has spoken into a system.


  • Baseline: A minimum or starting point used for comparisons (see also ICT Testing Baseline).
  • Bitmap image: A graphic image that may be purely decorative, or indicate the presence of a programmatic element. The word "bitmap" in this context does not imply any particular graphics file format.


  • CAPTCHA: Acronym for “Completely Automated Public Turing Test to tell Computers and Humans Apart."  A Turing test is any system of tests designed to differentiate a human from a computer.
  • Caret: An on-screen indication of the text input focus in a text edit field.
  • Communication Access Realtime Translation (CART): Live instant translation of the spoken word into text using a stenotype machine, notebook computer and realtime software. For CART services, search your agency intranet, or contact your agency relay official.
  • Cascading Style Sheets (CSS): CSS is a computer language used to style the presentation of a document written in a markup language, such as HTML. Along with HTML and JavaScript, CSS is a key technology of the World Wide Web. CSS enables presentation and content to be programmatically separated, including layout, colors, and fonts, which can improve content accessibility, and makes it possible to present the same page in different styles for different rendering methods such as desktops, mobile devices, for printing, and when using assistive technologies such as text-to-speech and Braille-based tactile devices. The CSS specifications are maintained by the World Wide Web Consortium (W3C). 
  • Client-side image map: Each "active region" in a picture can be assigned its own "link" (called a URL or "Uniform Resource Locator") that specifies what  to retrieve when a portion of the picture is selected. HyperText Markup Language (HTML) allows each active region to have its own alternative text, just like a picture can have alternative text.
  • Closed captions: Optional alternative text in a video or multimedia presentation; closed captions can be displayed and hidden by the user (see also: open captions).
  • Closed functionality: Characteristics that limit functionality or prevent a user from attaching or installing assistive technology. Examples of ICT with closed functionality are self-service machines, information kiosks, set-top boxes, fax machines, calculators, and computers that are locked down so that users may not adjust settings due to a policy such as Desktop Core Configuration.
  • Complex data table: A table that organizes data using more than a simple row/column structure. For example, categories of data may have subcategories, or data may belong to more than two categories (contrast with simple data table).
  • Conformance (Section 508): When electronic and information technology meets all of the applicable standards; for example, where a webpage meets W3C WCAG 2.0, Level A and AA guidelines.
  • Content: Electronic information and data, as well as the encoding that defines its structure, presentation, and interactions.


  • Data table: A table with information organized into categories.
  • Document: Logically distinct assembly of content (such as a file, set of files, or streamed media) that: functions as a single entity rather than a collection; is not part of software; and does not include its own software to retrieve and present content for users. Examples of documents include, but are not limited to, letters, email messages, spreadsheets, presentations, podcasts, images, and movies.
  • Digital service: Electronic delivery of information including content and data across various platforms and devices such as web or mobile.
  • Disability: A physical or mental impairment that substantially limits one or more major life activities, a record of such an impairment, or being regarded as having such impairment.


  • Electronic form: A computer program version of a paper form. Electronic forms can be programmed to automatically format, calculate, look up, and validate information for the user. Forms are commonly used in websites, mobile applications, and PDF documents.
  • Exceptions: See General Exceptions
  • Existing ICT: ICT that was procured, maintained or used on or before January 18, 2018.
  • Electronic and Information Technology (EIT): Superseded by Information and Communication Technology (ICT)
  • Executive agency: "'Executive agency' means an Executive department, a Government corporation, and an independent establishment," as per 5 U.S.C. § 105 (PDF)


  • Federal Acquisition Regulation (FAR): Principal set of rules in the Federal Acquisition Regulations System regarding  United States government procurement.
  • FedRelay: Federal Relay services expired February 13, 2022. FedRelay was a provides telecommunications services for federal agencies and tribal governments to conduct official business with individuals who are deaf or hard of hearing, or have speech disabilities. Agencies can access services formerly consolidated under FedRelay through Federal Communications Commission (FCC) Telecommunications Relay Service (TRS) and General Services Administration (GSA) Multiple Award Schedule Translation and Interpretation Services.
  • Focus: In a graphical user interface, a window (e.g., a button) or a location within a window (e.g., position of a text cursor or mouse pointer), to which the operating system will direct user input. Users can set the focus by using the keyboard, the mouse, or other input devices.
  • Frames: When creating a website, allows use of multiple, independently controllable sections on a web presentation. A typical use of the HTML frame function is to contain a selection menu in one frame, and use another frame to contain the space where the selected (linked to) files will appear (see also iFrame).
  • Functional Performance Criteria (FPC): The overall product evaluation criteria for technologies or components for which there is no applicable specific requirement(s) under the technical standards. These criteria ensure that the individual accessible components work together to create an accessible product. The FPC covers operation (including input and control functions) of mechanical mechanisms, and access to visual and audible information (the design functions of the webpage). These provisions allow people with sensory or physical disabilities to locate, identify, and operate the input, control, and mechanical functions of technologies and components. These provisions also allow access to the information provided, including text, static or dynamic images, icons, labels, sounds or incidental operating cues.


  • General exceptions: E202 of the Revised 508 Standards specifies which types of ICT are exempt from compliance.


  • Hardware: A tangible device, piece of equipment, or physical component of ICT, such as telephones, computers, multifunction copy machines, or keyboards.
  • Header attribute: An HTML data table cell attribute used to specify the associated header(s).
  • Hertz (Hz): A unit of frequency equal to one cycle per second.
  • Hyperlink: A URL that, when selected, takes a user to a section in the same webpage, or to a different webpage.
  • Hypertext: The clickable text on a webpage that links to another document or webpage.
  • Hypertext Markup Language (HTML): A set of tags and rules used to encode and format text, graphics, animation, sound, and other types of files on the internet.


  • ICT Testing Baseline: The ICT Testing Baseline document contains baseline tests for Revised 508 Standards for web conformance, which reference the WCAG 2.0 Level A and AA Success Criteria. The baseline tests establish the minimum tests and evaluation guidance that determine if web content meets Section 508 requirements. The baseline tests are not a test process.
  • iFrame (Inline Frame): An HTML structure that allows another HTML document to be inserted into an HTML page. Unlike the regular HTML frames function, which is used to divide the screen into multiple windows, the iFrame is typically used to insert an ad or small amount of text in the middle of a page (see also Frames).
  • Image map: An image on a webpage that links to multiple webpages or resources. The image is subdivided into regions (hotspots), each of which may link to a different resource. Server-side image maps cannot be made accessible and require redundant text links. Client-side image maps can be made accessible with alternative text description.
  • Inclusive design: See universal design
  • Information and Communication Technology (ICT): Information technology and other equipment, systems, technologies, or processes, for which the principal function is the creation, manipulation, storage, display, receipt, or transmission of electronic data and information, as well as any associated content. Examples of ICT include, but are not limited to: computers and peripheral equipment; information kiosks and transaction machines; telecommunications equipment; customer premises equipment; multifunction office machines; software; applications; websites; videos; and electronic documents {Section 508, E103.4 Defined Terms}.
  • Information Technology (IT): Has the same meaning as the term “information technology” set forth in 40 U.S.C. 11101(6).
  • Interactive element: Application content that a user may modify, activate, or use to input data.
  • Interface (user): The user interface allows the user to communicate with the operating system. The interface is composed of both devices (keyboard, mouse) and screen elements (menus, text, buttons, etc.).


  • Java: A programming language and computing platform first released by Sun Microsystems in 1995.
  • JavaScript: A programming language that allows for complex and interactive features on webpages. Along with HTML and CSS, JavaScript is one of three current standard web technologies and allows things like dynamically updated content and interactive maps, and responds to user actions such as mouse clicks, pointer movements, and key presses.


  • Keyboard: A set of systematically arranged alphanumeric keys or a control that generates alphanumeric input by which a machine or device is operated. A keyboard includes keys discernible by touch, used in conjunction with the alphanumeric value their function maps to on the keyboard interface. Keyboards are available in ergonomic or other specialized form factors to accommodate the needs of the user.


  • Label: Text, or a component with a text alternative, that is presented to a user to identify content. A label is presented to all users, whereas a name may be hidden and only exposed by assistive technology. In many cases, the name and the label are the same.
  • Layout Table: Layout tables are used to arrange elements on a document or webpage and intended to be ignored by assistive technology. (See also Data table)
  • Listserv: An automated mailing list program. GSA supports digital government communities of practice by hosting listservs that provide community members with an easy way to collaborate, ask questions, and share information. Learn how to manage your listserv subscription.


  • Menu: A set of selectable options
  • Multimedia (synchronized media): The combined use of several media, such as audio and visual (e.g., video or animation) to convey information or a live event, such as a television broadcast.


  • Name: Text used by software to identify a component for the user. A name may be hidden and only exposed by assistive technology, whereas a label is presented to all users. In many cases, the label and the name are the same. Name is unrelated to the name attribute in HTML.
  • Non-text element: An image, graphic, audio clip, or other feature that conveys meaning through either a picture or sound. Examples include: buttons, check boxes, input fields, pictures, and audio/video that’s embedded or streamed.
  • Non-web document: A document that is not a webpage, embedded in a webpage, or used in the rendering or functioning of webpages.
  • Non-web software: Software that is not a webpage, not embedded in a webpage, and not used in the rendering or functioning of webpages.


  • Open captions: Permanent alternative text in a video or multimedia presentation. The user cannot activate or deactivate open captions, because they are integrated into the video or presentation (see also closed captions).
  • Operable controls: A product component that requires physical contact to operate. Operable controls include, but are not limited to, mechanically operated controls, input and output trays, card slots, keyboards, and keypads.


  • Platform accessibility services: Services provided by a platform that enables interoperability with assistive technology. Examples include Application Programming Interfaces (API) and the Document Object Model (DOM).
  • Platform software: Software that interacts with hardware or provides services for other software. Platform software may run or host other software, and can isolate this software from underlying software or hardware layers. A single software component may have both platform and non-platform aspects. Examples include: desktop operating systems; embedded operating systems, including mobile systems; web browsers; plug-ins to web browsers that render a particular media or format; and sets of components that allow other applications to execute, such as applications which support macros or scripting.
  • Plug-in (web): A web plug-in is a small piece of software that adds features to a web browser. When the browser encounters a file extension (e.g., PDF, WAV, MOV), the browser will automatically view, or download and run, that file. Most plug-in readers are free. Examples include the PDF Acrobat reader.
  • Product: Something physical or digital (software), which is created through a development or engineering process.
  • Programmatically determinable: Ability of software to use author-supplied data to provide different user agents, including assistive technologies, a way to extract and present information to users in different modalities.
  • Programmatically exposed: Available from a software application to the operating system or other software applications via an API.
  • Public-facing: Content made available by an organization to members of the general public. Examples include, but are not limited to, an agency website, video, mobile app, blog post, or social media page.


  • Quality Assurance (QA): An activity to ensure an organization provides the best possible product or service to customers, often based on standardized testing methods.


  • Real-Time Text (RTT): Communication by which characters are transmitted by a terminal as they are typed. Real-time text is used for conversational purposes, and may also be used in voicemail, interactive voice response systems, and other similar applications.
  • Relay Conference Captioning (RCC): An internet-based technology offering real-time captioning; enables federal employees who are deaf or hard of hearing to join and participate in web and teleconference calls.
  • Revised 508 Standards: The standards for ICT developed, procured, maintained, or used by federal agencies subject to Section 508 of the Rehabilitation Act as set forth in 508 Chapters 1 and 2 (36 CFR part 1194, Appendix A), and Chapters 3 through 7 (36 CFR part 1194, Appendix C).


  • Script: A series of commands programmed in a non-HTML scripting language that displays content or performs a function. The content and function activated by scripts must be identified and accessible to assistive technology.
  • Scope attribute: A method of identifying row and column headers for HTML tables. Consider using the scope attribute for data tables with one- or two-levels of headers.
  • Search Engine Optimization (SEO): The practice of writing and structuring content to improve findability through organic search engine results.
  • Section 501 of the Rehabilitation Act: Prohibits discrimination in federal government hiring practices, and requires the development of affirmative action plans to increase the hiring, placement, and advancement of qualified people with disabilities.
  • Section 504 of the Rehabilitation Act: Prohibits discrimination against persons with disabilities in any federally-funded programs or activities, and requires such programs to be accessible to people with disabilities. Section 504 also prohibits disability-based job discrimination of any kind, and requires that employers make reasonable accommodation for employees with disabilities.
  • Self contained, closed products: ICT products that generally contain embedded software, and are commonly designed so that a user cannot easily attach or install assistive technology. These products include, but are not limited to, information kiosks and information transaction machines, copiers, printers, calculators, fax machines, and other similar products (superseded in the Revised 508 Standards by closed functionality).
  • Sensory characteristics: Instructions for understanding and using content that don’t rely solely on the sensory characteristics of components, such as shape, size, visual location, orientation, or sound.
  • Server-side image map: A clickable image for which the link information resides on the server. When a user clicks on a server-side image map with a mouse, the web browser attaches the pixel coordinates (x,y) of the click to a given server link. The server interprets the coordinates and performs some action. Server-side image maps cannot be used by keyboard.
  • Simple data table: A data table that represents each category of data with one row or column of cells. The meaning of each cell is based on its contents and its row and/or column position. Simple data tables can represent 2-dimensional data (contrast with complex data table).
  • Social media: A collection of internet-based communities where users interact with each other. This includes web forums, wikis, and user-generated content (UGC) websites. Examples of social media platforms commonly used by federal agencies include Facebook, LinkedIn, Twitter, YouTube, and Instagram.
  • Software: Programs, procedures, rules, and related data and documentation that direct the use and operation of ICT, and instruct it to perform a given task or function. Software includes, but is not limited to, applications, non-web software, and platform software.
  • Software tools: Software for which the primary function is the development of other software. Software tools usually come in the form of an Integrated Development Environment (IDE), and are a suite of related products and utilities. Examples of IDEs include Microsoft® Visual Studio®, Apple® Xcode®, and Eclipse Foundation Eclipse®.
  • Style sheets: A simple mechanism for customizing webpage formats (defining fonts, colors of titles, paragraph spacing, etc.) to create a separation of presentation and content.
  • Synchronized captions: A text alternative in a multimedia video or animation that is displayed to make the audio portion of the content accessible to users who are deaf or hard of hearing. Captions include the description of sounds (i.e., "[the dog barks]"), symbols, or icons to represent the type of content, such as a musical note to represent music.
  • Synchronized media (multimedia): The combined use of several media, such as audio and visual, to convey information.


  • Table: A two-dimensional group of rectangular cells organized into rows and columns. Tables can be used to display information, or used as a method of laying out information.
  • Table header: The name of a category of data in a data table row or column. In a simple data table, column headers are provided in the first row and apply to the data cells in their respective columns. Similarly, row headers are provided in the first column and apply to the data cells in their respective rows. In a complex data table, a column header may be defined in any row, and may apply to multiple columns or to a few cells in a column, and a row header may be defined in any column, and may apply to multiple rows or to a few cells in a row.
  • Telecommunications Relay Services (TRS): Telecommunications Relay Services (TRS) allow persons who are deaf, hard of hearing, deafblind, or have speech disabilities to communicate by telephone in a manner that is functionally equivalent to telephone services used by persons without such disabilities.
  • Telecommunications: The signal transmission of information of the user’s choosing, between or among points specified by the user, without change in the form or content of the information as sent and received.
  • Terminal: Device or software that provides the user interface through which the end user directly interacts. For some systems, the software that provides the user interface may reside on more than one device such as a telephone and a server.
  • Text: A sequence of characters that can be programmatically determined, and that expresses something in human language.
  • Text file description: The conversion of the visual content of a complex image, or visual-only video file, into text.
  • Thick client: A fully-featured computer connected to a network that can perform most processing functions on its own, independent of a central server. It becomes a “client” of the server only when it needs to access programs or files not stored on a local drive.
  • Thin client: A computer or computer program designed to work with a host-server computer in a client/server computing model. A thin client depends heavily on its server to fulfill its traditional computational roles.
  • Transcript: The conversion of the spoken language of an audio file into a text format.
  • Trusted Tester: The Trusted Tester Process is a manual test approach developed by the Department of Homeland Security (DHS) that aligns with the ICT Testing Baseline, and provides repeatable and reliable conformance test results. DHS offers training and formal accessibility testing certification for using the DHS Trusted Tester Process. Agencies that adopt the Trusted Tester Process only accept test results from individuals who have been certified as Trusted Testers.
  • TTY: Equipment that enables interactive text based communications through the transmission of frequency-shift-keying audio tones across the public switched telephone network, such as a computer with TTY emulating software and modem. TTYs include devices for real-time text communications and voice, and text intermixed communications, such as voice or hearing carry-over.


  • U.S. Access Board: The U.S. Access Board is a federal agency that promotes equality for people with disabilities through leadership in accessible design and the development of accessibility guidelines and standards for the built environment, transportation, communication, medical diagnostic equipment, and information technology (Section 508).
  • Undue burden: An action that requires significant difficulty or expense. In determining whether an action would result in an undue burden, an agency shall consider all agency resources available to the program or component for which the product is being developed, procured, maintained, or used.
  • User Agent : As per definition, "[a] user agent is any software that retrieves and presents Web content for end users or is implemented using Web technologies. User agents include Web browsers, media players, and plug-ins that help in retrieving, rendering and interacting with Web content. The family of user agents also includes operating system shells, consumer electronics with Web-widgets, and stand-alone applications or embedded applications whose user interface is implemented as a combination of Web technologies."
  • User interface element: Elements of an application that convey information.
  • Uniform Resource Locator (URL): What a user types into a browser to find the location of a resource on the web.
  • Universal design: The design and composition of an environment so it can be accessed, understood, and used to the greatest extent possible by all people, regardless of their age, size, ability or disability. Universal design is also referred to as inclusive design.


  • Variable Message Signs (VMS): Non-interactive electronic signs with scrolling, streaming, or paging-down capability. An example of a VMS is an electronic message board at a transit station that displays gate and arrival time information.
  • Video-only (pre-recorded): An alternative for an audio track, or time-based media that presents equivalent information for prerecorded, video-only content.
  • Voice over Internet Protocol (VoIP): A technology that provides real-time voice communications. VoIP requires a broadband connection and equipment compatible with internet protocol.
  • Voluntary Product Accessibility Template (VPAT®): A document template established by the Information Technology Industry (ITI) Council which evaluates how accessible a particular product is, according to Section 508 Standards. Vendors use this template to produce a self-disclosing document, called an Accessibility Conformance Report (ACR), which details each aspect of the Section 508 requirements and how the product supports each criteria. ACRs, based on VPAT®, are used by buyers to understand how accessible a product is, and any potential deficiencies.


  • Web Content Accessibility Guidelines (WCAG): Guidelines established by the World Wide Web Consortium (W3C) under their Web Accessibility Initiative (WAI). The revised Section 508 standards harmonize with WCAG version 2.0 A & AA
  • Webpage: A non-embedded resource obtained from a single Universal Resource Identifier (URI) using HyperText Transfer Protocol (HTTP) plus any other resources that are provided for the rendering, retrieval, and presentation of content.
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Updated: November 2022

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