Georgia Tech Research Institute
 

Glossary Definitions

accessibility feature
An accessibility feature is a built-in feature of a product that is labeled as an accessibility feature and is documented according to relevant industry documentation standards. Accessibility features can normally be turned off and on by the user. Examples of these features include: reversing the color scheme (to assist people with low vision), showing a visual prompt when an error tone is sounded (to assist persons who are deaf or hard of hearing), or providing "sticky keys" that allow a user to press key combinations (such as control-C) sequentially rather than simultaneously (to assist persons with dexterity disabilities). This requirement prohibits software programs from disabling these features when they have been activated prior to running the application.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

alternate formats
Formats that are usable by people with disabilities. Examples of alternate formats include ASCII text, large print, Braille, and recorded audio.

alternate methods
Different means of providing information, including product documentation, to people with disabilities. Alternate modes may include, but are not limited to, voice, fax, relay service, TTY, Internet posting, captioning, text-to-speech synthesis, and audio description.

(Source: www.section508.gov)

alternate modes
See alternate methods.

alternative form of identification or activation
For this standard, an alternative control is defined as a non-biometric control that conforms to the applicable standards of part 1194 of Section 508.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Self Contained, Closed Products")

alternative text
Alternative text ("alt text") means adding words to represent the purpose of a non-text element. This provision requires that when an image indicates a navigational action such as "move to the next screen" or "go back to the top of the page," the image must be accompanied by actual text that states the purpose of the image. This provision also requires that when an image is used to represent page content, the image must have a text description accompanying it that explains the meaning of the image.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Web-based Intranet and Internet Information and Applications")

ambient noise
Ambient noise is the background sound of an environment (for example, people typing and phones ringing in an office environment); it is the noise over which the object of interest must be heard.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Self Contained, Closed Products")

analog television display
An analog television display is any device that displays analog television signals or other signals such as those originating from DVD or video tape. In addition to standard television displays, these display devices also include projectors that have analog video input and include analog TV display circuitry, and computers that display analog television signals.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Video and Multimedia Products")

animation
Animation is automated visual movement created by and under the control of the software application that is displayed on a user interface. Note this definition does not include video, which is the result of differences in the images within individual video frames, and is not created by the display application. For this standard, assume that self-scrolling and moving text are considered animation.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

applet
An applet is a program that is part of content, and that the user agent executes.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

application programming interface
An application programming interface (API) is a set of subprograms that applications may use to request and carry out lower-level services performed by an operating system. The API is a standard way for programs to communicate with one another, including the operating system and with input and output devices. For instance, the application programming interface affects how programs display information on a monitor or receive keyboard input via the operating system.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

assistive technology
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. Examples include a screen reader, a magnifying glass, and a head stick.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

audio description
Audio description is an audible description of the visual content of a presentation, synchronized with the existing soundtrack.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Video and Multimedia Products")

audio information
Audio information is electronic sound necessary for the comprehension of the content of a video or multimedia production.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Video and Multimedia Products")

audio transducer
A transducer is a device that transforms energy from one form to another. An example of an audio transducer is the speaker in a telephone handset, which transforms electrical energy to sound.

auditory output
In the context of this standard, auditory output refers to voice output.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Self Contained, Closed Products")

biometric forms of user identification or control
Biometric controls refer to controls that are activated by matching a specific biological feature (e.g., voiceprint or finger print) of the user to an existing record of that feature (perhaps based on specific criteria). Other examples include retinal scans and fingerprint identification.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Self Contained, Closed Products")

bitmap image
A bitmap image is a graphic image indicating the presence of an interface element. Note that bitmap in this standard does not imply any particular graphics file format. This provision applies to those bitmap images that are used to indicate an action. An image used strictly for decoration is not covered by this provision.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems"; Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Software Applications and Operating Systems")

captions
Like subtitles, captions display spoken dialogue as printed words on a television screen or computer monitor. Unlike subtitles, captions are specifically designed for hard of hearing and deaf viewers to enable their full participation when viewing video or multimedia productions. Captions are carefully placed to identify speakers. They often include information regarding on- and off-screen sound effects, such as music or laughter. Captions also hold secondary benefits for people who are learning a foreign language, learning how to read, or watching TV in a noisy area, as well as those who understand best by processing visual information. Captions come in two forms: open or closed captioning.

Open captions are captions that are displayed automatically as part of the video, without having to be selected by the user.

Closed captions are captions that normally do not appear as part of the video portion of a multimedia presentation unless the viewer has selected them to appear. The person viewing the presentation must be using technology that includes a closed caption decoder. The decoder will allow the otherwise-hidden data within the television signal to be displayed on the user's TV screen or computer monitor. Many newer television models allow viewers to toggle captions on or off with ease.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Video and Multimedia Products")

color blindness
Color blindness, also known as color deficiency, is the partial or total inability to recognize or distinguish specific colors.

color coding
Color coding is using color as a means to distinguish one item, or state of an item, from another. For example, a light shows green if a device is ready to operate, and red otherwise.

contact-sensitive controls
Contact-sensitive controls are controls that are activated when they sense a person's touch. This does not imply that they require contact with a person's skin (they may be activated by a pencil eraser, for example), but that they require little pressure to activate.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Self Contained, Closed Products")

current focus
Current focus refers to the interactive interface element within a user interface that is currently active. For example, when a menu item in a program is highlighted - meaning that if the user clicks the mouse or presses the enter key - the feature will activate and that item will take the focus.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

data table
A table used to represent information in a tabular format.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

Complex data tables are defined as having two or more levels of row or column headings or headings that span multiple rows or columns. Complex data tables require additional markup to explicitly associate the heading with the data.

(Source: IBM Accessibility Center: Developer Guidelines)

decibel (dB)
A decibel is a unit of relative sound intensity, abbreviated dB.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Telecommunications Products")

disability
A physical or mental impairment that substantially limits one or more of the major life activities.

(Source: U.S. Department of Education)

discerned textually
Discerned textually means able to be represented with words without a lengthy description.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

disrupt
To disrupt is to disturb normal appearance or behavior in a perceptible way.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems"; Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Software Applications and Operating Systems")

documents
Documents are named, structured units of text, images, or other elements, and in terms of this standard can also be web pages.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

DTMF
Dual-tone multi-frequency (DTMF) tones are those used by touch-tone phones for tone dialing.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Telecommunications Products")

DTMF-enabled TTY configuration
A DTMF-enabled TTY configuration is a TTY that either produces DTMF tones itself, or can work together with a DTMF tone producing system (such as a telephone) to generate DTMF tones.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Telecommunications Products")

electronic and information technology (E&IT)
E&IT includes information technology and any equipment or interconnected system or subsystem of equipment that is used in the creation, conversion, or duplication of data or information. The term E&IT includes, but is not limited to, telecommunications products (such as telephones), information kiosks and transaction machines, websites, multimedia, and office equipment such as copiers and fax machines. The term does not include any equipment that contains embedded information technology that is used as an integral part of the product, but the principal function of which is not the acquisition, storage, manipulation, management, movement, control, display, switching, interchange, transmission, or reception of data or information. For example, HVAC (heating, ventilation, and air conditioning) equipment such as thermostats or temperature control devices, and medical equipment where information technology is integral to its operation, are not information technology.

electronic form
In the context of accessibility standards, an electronic form is an interactive online data entry tool, often implemented in HTML. Electronic forms consist of various types of controls (e.g., data entry fields, checkboxes, radio buttons) and associated labels and instructions.

equivalent alternatives
Equivalent alternatives include captioning provided for audio information, audio description of visual information, or other alternative presentations of information that fulfills the same function or purpose upon presentation to the user. This provision requires that when an audio portion of a multimedia production is captioned, as required in 1194.22(a), the captioning must be synchronized with the audio. Synchronized captioning would be required so someone reading the captions could also watch the speaker and associate relevant body language with the speech.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Web-based Intranet and Internet Information and Applications")

expansion slot
A receptacle on a computer motherboard into which a printed circuit board can be inserted to add additional functionality to a computer system.

field element
A field element is a user interface element that appears within an electronic form; it is where the user enters information to complete the form.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

flashing element
A flashing element is an interface element that has an intentional cyclic variation in display. For standard 1194.21(k), assume "other elements" means any interface element with a flashing or blinking display, including turning graphics on and off or repeatedly changing between different images on the screen.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

flicker
Flicker is an unintentional and undesirable cyclic variation in a display or a screen image.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

frame
A frame is used on a website to provide a means of visually dividing the computer screen into distinct areas that can be separately addressed.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

freestanding, non-portable
In the context of accessibility standards, a freestanding, non-portable device is a device that is not permanently installed as part of a larger structure but is intended to be used in a single location. Such devices allow some freedom of placement during installation. Office multi-function copiers and kiosk-style ATMs are examples of freestanding, non-portable devices.

functional text
Functional text is text that when read conveys an accurate message as to what is being displayed by the script or that describes what action the script will perform.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

gain
Gain is the amount of increase in signal power, usually a ratio of output to input power. Gain is often expressed in units of decibels when dealing with audio gain. Positive decibel gain indicates amplification; negative decibel gain indicates attenuation.

HCO
HCO stands for "hearing carry over". This term refers to a strategy for using TTYs. HCO allows a person with a speech disability to hear a response from their party directly. HCO is often used in conjunction with a relay service.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Telecommunications Products")

hearing aid compatibility
Hearing aid compatibility (HAC) commonly refers to magnetic leakage around a telephone receiver. Hearing aid users desire a phone that emits such a magnetic field because it enables them to listen through a phone handset held up to their ear without getting an annoying squealing sound (acoustic feedback). They accomplish this by turning off their hearing aid microphone and listening "inductively" (via magnetism).

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Telecommunications Products")

hertz (Hz)
The hertz is the international unit of frequency and is equal to one cycle per second.

image map
An image map is a picture (often an actual map) on a web page that provides different links to other web pages, depending on where a user clicks on the image.

On a 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 web page to retrieve when a portion of the picture is selected. HTML allows each active region to have its own alternative text, just like a picture can have alternative text.

On a server-side image map, clicking on the location only specifies the coordinates within the image when the mouse was depressed. The ultimate selection of the link or URL must be deciphered by the computer serving the web page.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Web-based Intranet and Internet Information and Applications")

incremental volume control
Incremental volume control is volume control that allows more than two levels. There is a minimum and maximum level, as well as some number of other volume levels that fall between the minimum and maximum. The size of the increment may be such that either a continuous or variable volume control may be provided.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Self Contained, Closed Products")

individual display attribute
An individual display attribute is a visual display characteristic that has a user selectable setting.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

industry standard connector
An industry standard connector is a plug that is not proprietary, and is assumed to be a 2.5 mm or 3.5 mm audio jack.

interactive interface element
A user interface element is any component of an application user interface intended to allow the user to access information or perform an action. Examples of user interface elements include buttons, checkboxes, menus, toolbars, and scroll bars.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

interoperability
Interoperability refers to the ability of independent, distributed software components to communicate with one another and operate together as part of a larger system. This includes the ability of two or more systems or components to exchange data and mutually use the information that has been exchanged. For this standard, providing interoperability between an otherwise self contained closed product and assistive technology is permitted. However, any product that does provide interoperability with assistive technology must be usable without that technology as well, hence making it a self contained closed product.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Self Contained, Closed Products")

IVRS
Interactive voice response systems include systems such as voice mail, recordings that require the user to select the department they'd like to connect to, or the job line announcements they would like to hear. They involve voice output that is retrieved through interaction with the telephone keypad.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Telecommunications Products")

key repeat
Key repeat is a function of keyboard keys and other buttons used for data entry in which the key activates repeatedly when held down. Generally, keys activate once when first depressed, and if the key remains depressed, the key will begin to repeat at some key repeat rate after some key repeat delay time elapses.

light reflectance value (LRV)
Light reflectance value is a measure of how much light is reflected from a surface. It is expressed as a percentage, where black has a value of 0% and white has a value of 100%.

locking keys/toggle controls
Toggle controls are controls that have two states, such as "on" and "off." Locking keys on computer keyboards (such as Caps Lock, Num Lock, and Scroll Lock) are common examples of toggle controls.

magnetic wireless coupling
For a telecommunications product, magnetic wireless coupling (also known as inductive coupling) is a coupling between devices (for example, between a telephone and a hearing aid) that is accomplished through variance of a shared magnetic field. When a hearing aid is inductively coupled to a telephone, the hearing aidís microphone is turned off to eliminate unwanted ambient noise and signals are only received from magnetic fields generated by the telephone.

(Source: United States Patent and Trademark Office's "Section 508 Reference Guide")
mechanically operated control
A mechanically operated control is a control that is operated by means of direct manipulation of a physical device (such as a toggle switch or a keyboard key), as opposed to a representation of a control on a touchscreen or other display.

mobility impairments
Mobility impairments are the consequence of a number of conditions (including arthritis, cerebral palsy, multiple sclerosis, Parkinsonís disease, spinal cord injury, stroke, and others) that restrict or complicate an individualís capacity for free movement. Individuals with mobility impairments may find it difficult to use certain control devices such as keyboards, mice, or small buttons and switches. These individuals may use assistive technologies such as voice recognition software or specialized keyboards and mice.

multimedia presentation
A multimedia presentation is any presentation of more than one type of media, typically both audio and visual information.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

multimedia production
The term "multimedia productions" refers to productions that present information in more than one sensory mode, e.g., both audibly and visually. For instance, streaming video with a soundtrack is a multimedia production. A show broadcast through a Federal military radio station is audio only and therefore not covered by this captioning standard. (However, the procurement of electronic and information technology necessary to operate the radio station would be covered under the 508 standard.)

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Video and Multimedia Products")

newton (N)
A newton is a unit of force. 22 newtons equal 5 pounds of force.

non-text element
A non-text element is an image, graphic, audio clip, or other feature that conveys meaning through a picture or sound. Examples include buttons, check boxes, pictures and embedded or streaming audio or video.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Web-based Intranet and Internet Information and Applications")

operable control
A component of a product that requires physical contact for normal operation. Operable controls include, but are not limited to, mechanically operated controls, paper trays, card slots, keyboards, or keypads.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Self Contained, Closed Products")

PDF
Adobe® Portable Document Format (PDF) is a publicly available specification used by standards bodies around the world for more secure, reliable electronic document distribution and exchange. Adobe PDF has been adopted by governments and enterprises to streamline document management, help increase productivity, and reduce reliance on paper. Today, Adobe PDF is a standard, reliable format for the electronic submission of drug approvals to the U.S. Food and Drug Administration (FDA) and for electronic case filing in U.S. federal courts. It is also a standard format used for advertising pages, in newspapers and magazines.

(Source: Adobe)

pinch
Use of two digits, usually thumb and forefinger, to apply pressure to opposite sides of an object.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Telecommunication Products")

plug-in
A plug-in is a program that runs as part of the user agent and that is not part of content. Users generally choose to include or exclude plug-ins from their user agent. These add-on programs or "plug-ins" can be downloaded and installed on the user's computer, making it possible for their web browsers to display or play the content of the files with proprietary formats when these files are included as part of a web page.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

production
A production is the end product of the process of producing a video or multimedia presentation. This is distinct from the in-process data (the multimedia raw footage) acquired in the preparation or development of a final production.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Video and Multimedia Products")

program element
See interactive interface element.

programmatically exposed
Available from a software application to the operating system or other software applications via an application programming interface (API), which is a standard way for programs to communicate with each other.

(Source: United States Patent and Trademark Office's "Section 508 Reference Guide")

redundant text link
A redundant text link is a link that points to the same location as the active image region, or to another location that is equivalent to that referenced by the active image region.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

reference plane
The Section 508 1194.25(j) accessibility standards define a vertical plane that is 48 inches wide, centered on the control under evaluation, and located at the maximum horizontal protrusion of the device within the 48 inch span. This vertical plane is used as the reference from which the horizontal displacements of controls on the device are measured.

relay service
A telecommunications relay service (TRS) is a telephone interpreting service for people with communication disabilities. It enables a TTY user to converse with a non-TTY user. Relay service operators are called Communication Assistants (CAs) and serve as third parties to facilitate conversations by typing or speaking information as appropriate. Relay services are available without charge 24 hours per day. These and other TRS provisions are mandated under Title IV of the Americans with Disabilities Act. An FCC report and order mandates 7-1-1 as a toll-free number to use in accessing a relay service. The Federal Relay Service is one of several relay services available throughout the country.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Telecommunications Products")

repetitive navigation links
Repetitive navigation links are a set of routine navigation links that appear on the top or the side on a web page.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

scripting language
A scripting language is a programming language that is used to manipulate, customize, and automate the facilities of an existing system. Standard 1194.22(l) refers only to the use of scripting languages for creating and displaying dynamic web content.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

secondary audio channel
The most common method of broadcasting audio description is through the Secondary Audio Program (SAP) feature of stereo televisions. Each television channel has what is called a "secondary audio channel" associated with it, which is an auxiliary sound channel that can be transmitted in addition to a television station's main audio channel. The secondary audio channel may contain audio descriptions or foreign language translations of dialogue. If used to deliver audio descriptions, SAP can greatly enhance the multimedia experience for those who are blind or who have low vision. When television tuners, including tuner cards for use in computers, are equipped with SAP playback circuitry, people who are blind or who have low vision may access whatever audio description has been associated with the presentation.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Video and Multimedia Products", Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Video and Multimedia Products")

Section 508
Section 508 is a 1998 amendment to the Rehabilitation Act of 1973. It requires that when federal departments and agencies procure, develop, maintain or use electronic and information technology (E&IT), subject to commercial availability, they must ensure that it complies with the Section 508 standards developed by the Architectural and Transportation Barriers Compliance Board (Access Board), unless doing so would pose an undue burden on the federal department or agency. The purpose of the law is to ensure that federal employees and members of the public with disabilities have access to the same information and data as employees and members of the public without disabilities.

self contained, closed products
Products that generally have embedded software. Typically they are designed such that assistive technology cannot be attached or installed. For example, someone could attach a screen reader to a computer which meets the Section 508 standards, but would not be expected to attach a screen reader to a copier machine; a copier machine is an example of a self-contained, closed product. Other examples of self contained, closed products include calculators, fax machines, information transaction machines, and information kiosks. Note that a personal digital assistant (PDA) is not necessarily a self contained, closed product.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Self Contained, Closed Products")

standard signal level
In the context of 1194.25(e), a standard signal level is an audio output signal level sufficient to drive headphones or other personal listening devices.

sufficient time
In the context of accessibility standards, sufficient time means a period of time that will allow even the slowest users to complete a task. A good rule of thumb for accommodating the slowest users is to allow up to 10 times the amount of time it would take an average user to complete the task. (Source: accessIT's "Accessibility Guidelines for Application Software")

structured PDF
A structured PDF is a somewhat accessible PDF. Structured PDFs have no tags, no alternative text for images, no definition of table column and row headers, and screen readers may not read the text in the PDF in the correct order.

style sheet
A style sheet is a collection of formatting instructions stored in a file that determines how the layout of the documents to which it is attached are presented (e.g. displayed on screens, printed, or pronounced).

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

synchronized
Synchronized means having common timing and coordination of execution.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Web-based Intranet and Internet Information and Applications")

tactilely discernible
Keys are tactilely discernible if the user can feel each one individually, such that they can be distinguished from all others (without being activated) and can be properly identified. The user should be able to, for example, count out the keys appropriately to activate a desired function. If not tactilely discernible, users may count too many or too few keys. Ways to differentiate keys are with spacing, or tactile indicators, and by raising them off the surface of the device.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Self Contained, Closed Products")

tagged PDF
Tagged PDFs were developed by Adobe to make PDFs more accessible to screen readers. Tagged PDFs represent various components of a document as tag elements, including chapters, heading styles, blocks of text, tables, and graphics. The hierarchy of these tagged elements represents the reading order. This type of PDF allows the creator of the PDF to do things like (a) specify the intended reading order by tagging various groups of text and other page elements, (b) add alternative text for images, (c) specify the native document language for optimal reading by a screen reader, and (d) re-order text on a page when necessary due to screen size or font characteristics.

telecoil
A telecoil is a small, tightly-wrapped piece of wire that, when activated, picks up the voice signal from the electromagnetic field that leaks from compatible telephones. Users of telecoil-equipped hearing aids are able to communicate effectively over the telephone without feedback and the amplification of unwanted background noise.

(Source: FCC Consumer Facts: Hearing Aid Compatibility Compliance for Traditional Telephone Equipment)

text equivalent
A text equivalent means adding words to represent the purpose of a non-text element. This provision requires that when an image indicates a navigational action such as "move to the next screen" or "go back to the top of the page," the image must be accompanied by actual text that states the purpose of the image. This provision also requires that when an image is used to represent page content, the image must have a text description accompanying it that explains the meaning of the image.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Web-based Intranet and Internet Information and Applications")

textual information
Textual information is any information presented using words and characters. Note that an image of text is considered textual information.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Software Applications and Operating Systems")

timed response
When a time-out is set, the user has a fixed amount of time to respond (to finish a form, for example) before being logged out of the system. Time-outs are set to protect the user's privacy.

touch-opreated control
Touch-operated controls are controls operated by human touch, or objects such as a mouthstick, stylus, or pencil.

touchscreen
Touchscreens, touch panels or touchscreen panels are display screens that have a transparent overlay that is pressure-sensitive so that you can enter instructions and data by touching the screen.

(Source: Wikipedia)

TTY
A TTY (teletypewriter) is a data terminal that allows a person with a communication disability to use the telephone. TTYs traditionally have been stand-alone devices with a keyboard and an electronic display for reading text. TTYs send and receive tones which are converted to text. TTYs transmit and receive baudot code at a rate of 45.5 baud. Baudot refers to the code made from bits of electronic information. Baudot is considered to be an antiquated code. Baud refers to the speed at which data can be transmitted. Some TTYs may transmit at a faster speed using proprietary protocols or American Standard Code for Information Interchange (ASCII). ASCII is a more conventional code, commonly used by computers and other devices that transmit data. It is possible to enable some computers to function as TTYs if appropriate communication software (and sometimes a different modem) is installed. Some TTYs can connect directly to the phone or phone line, thus reducing the possibility of noise interfering with the data. Depending on the type of phone, a TTY might connect via a standard RJ-11 phone jack or a 2.5 mm audio jack. A variety of TTY styles exist that include models without acoustic coupling ability and models without keyboards. People select and use TTYs differently depending on their communication preferences and the nature of their disabilities.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Telecommunications Products")

tuner card
A tuner card is a circuit board that enables a computer to receive television broadcasts. This product is an example of what the industry calls "convergence" and represents a way in which the functions historically provided by TV, PC, cable and Internet products are merging onto multi-function devices. Tuner cards can be internal or external and can work with laptop or desktop computers.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Video and Multimedia Products", Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Video and Multimedia Products")

unstructured PDF
An unstructured PDF is a PDF in which the content is presented only as images. Unstructured PDFs are typically created by scanning paper documents. Screen readers are unable to access any of the content of unstructured PDFs, rendering them inaccessible.

usable by people with disabilities
A product is "Ďusable by people with disabilities' if the product complies with provisions 1194.25(b) - (j)(4), plus any other technical provisions that apply, plus the functional performance provisions of 1194.31."

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Self Contained, Closed Products")

user interface element
See interactive interface element.

VCO
VCO stands for "voice carry over". This term refers to a strategy for using TTYs. VCO allows people who are hard of hearing or oral deaf (deaf with intelligible speech) to use a TTY without typing. They only use the TTY for reading during the inbound direction of the call. They talk to their party by speaking into a microphone. VCO is often used in conjunction with a relay service.

(Source: Access Board's "Guide to the Section 508 Standards for Electronic and Information Technology: Telecommunications Products")

video production
A multimedia production containing both visual and auditory information delivered on a videotape.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Video and Multimedia Products")

visual impairments
Visual impairments are the consequence of a number of conditions (including retinal degeneration, cataracts, glaucoma, corneal disorders, and brain and nerve disorders) that result in a functional loss of vision. The degree of functional loss can range from low vision to total blindness. Symptoms of low vision can include dimness, haziness, extreme far-sightedness or near-sightedness, color blindness, and tunnel vision, among others.

visual information
Visual information is key visual elements necessary for comprehension of the content of a video or multimedia production.

(Source: Accessibility Forum's "Quick Reference Guide to Section 508 Resource Documents: Video and Multimedia Products")

well-defined
In the context of 1194.21(c), conspicuous and readily distinguishable.