A

AAP (American Association of Publishers)

Organization of publishers that have defined various standard DTDs for SGML, which have been used as the basis for the latest ISO DTDs.

See also [ISO 12083]

absolute link

A hypertext link that identifies a resource by its full address.

See also [relative link]

absolute path

An XPath navigation method that locates an object by its unique identifier, rather than by its contextual location.

See also [relative path]

abstract syntax

An SGML concept not applicable to XML that allows SGML markup syntax to be configurable, so that a start-tag could, for example, be described by '[para]' instead of '<para>'.

accent

A diacritical mark that modifies a base letter. For example, 'é'. The ISOlat1 set of entities defines references for common European accented characters. For example, '&eacute;'.

access server

A computer that provides access to remote users, providing transparent access to remote networks. Sometimes called a remote access server.

address resolution protocol

See [ARP (address resolution protocol)A TCP/IP protocol for locating the physical address of a node on the network.]

Adobe Acrobat

A program that displays page images on-screen, or outputs them to paper, using the PDF data format. A suitable electronic publishing method when the screen presentation must exactly match page formatting.

agent

A program that operates on a user's behalf, performing its task in the background and delivering results at the end of its task. A Web agent may roam over the Internet for information of interest to the user.

American Standard Code for Information Interchange

See [ASCII (American Standard Code for Information Interchange) [pronounced 'ass-key'] The most popular scheme for representing common characters (Latin alphabet, Arabic digits and typewriter symbols) in computer memory. Defined by ANSI (American National Standards Institute). A unique 7-bit value is assigned to each character, including '65' for the letter 'A' and '49' for the digit '1' (the value of a character should not be confused with a digit character, such as '1'). The values 0 to 31 are non-printing control characters; 32 to 127 represent letters, numbers and symbols. The only relevant alternative is EBCDIC, used on IBM mainframe systems.]

amp

The name of a reserved entity that represents the ampersand character, '&', used to avoid confusing a data character with an entity reference delimiter.

ancestor

A concept derived from the family tree describing an element that encloses the subject element, either directly as a parent, or indirectly as part of a larger hierarchy of elements. For example, a Book element would be the ancestor of a Paragraph, and also of the Chapter containing the Paragraph.

See also [child]

See also [sibling]

ancestor::

An XPath expression that selects an ancestor of the current node, with the given name.

See also [descendant::]

anchor

A tag embedded in the text that serves as the source or destination of a hypertext link. The link is 'anchored' because it stays with the relevant text if it is moved due to insertions or deletions earlier in the document. Sometimes used to describe an element that serves as both the target and source ends of a link.

and

Used in an expression in XPath to test two sub-expressions, returning true only if both sub-expressions are true.

See also [or]

ANY

A keyword used to indicate that an element may contain all other elements defined in the DTD (including itself). Rarely used in practice, due to the lack of constraint on structure it encourages.

API (Application Program Interface)

A specification for the interface of a software package by which other programs can utilize that package. An XML processor must have an API through which applications can receive XML data.

See also [PEDecl{72} (Parameter Entity Declaration)]

See also [DOM (Document Object Model)]

apos

The name of a reserved entity that represents the apostrophe character, ' ' ', used to avoid confusing a data character with an attribute value delimiter.

applet

A self-contained program that runs in a specific environment, usually a Web browser.

See also [apos]

applet (Java)

A semi-compiled Java program accessed by a Web browser for activation on the local system. Source code has an extent of '.java'. Semi-compiled code, or 'bytecode', has an extent of '.class'. Machine-specific compilers are available from http://java.sun.com/download.html.

arc

A connection between two nodes, creating a relationship.

architectural form

The use of XML constructs to add a further layer of meaning. A syntax that rests upon XML, just as XML rests upon Unicode. Only specialist software applications make use of the additional information. Typically, a processing instruction format, element name, or attribute name and value provides the extra information for example applications.

See also [ICADD (International Committee for Accessible Document Design)]

See also [XLink(XML Linking Language)]

ARP (address resolution protocol)

A TCP/IP protocol for locating the physical address of a node on the network.

ASCII (American Standard Code for Information Interchange)

[pronounced 'ass-key'] The most popular scheme for representing common characters (Latin alphabet, Arabic digits and typewriter symbols) in computer memory. Defined by ANSI (American National Standards Institute). A unique 7-bit value is assigned to each character, including '65' for the letter 'A' and '49' for the digit '1' (the value of a character should not be confused with a digit character, such as '1'). The values 0 to 31 are non-printing control characters; 32 to 127 represent letters, numbers and symbols. The only relevant alternative is EBCDIC, used on IBM mainframe systems.

See also [ISO/IEC 646:1991]

See also [ISO/IEC 8859/1]

See also [Unicode]

at-rule

A CSS rule that is used to create definitions for objects that do not map to elements, such as page layout characteristics. So called because it is identified by a 'commercial at' symbol', '@'.

AttDef^{53} (Attribute Definition)

The part of an attribute list declaration (AttlistDecl^{52}) that describes one attribute for the element, including its name and any restrictions on the value it can take.

ATTLIST

keyword The keyword that identifies an attribute declaration, used to declare and define the content of one or more attributes.

AttlistDecl^{52} (Attribute list Declaration)

The markup used to define attributes and assign them to a specific element. Although there may be more than one attribute list declaration for an element, for compatibility with SGML only one should be used.

attribute

An element parameter that modifies or refines the meaning of the element, and consists of a name and a value. The attribute is named to distinguish it from other attributes and values in the same element.

Attribute

See [attribute An element parameter that modifies or refines the meaning of the element, and consists of a name and a value. The attribute is named to distinguish it from other attributes and values in the same element.]

attribute::

An XPath expression that selects a given attribute of the current node.

Attribute^{41}

The name and value of a single attribute instance, embedded in the start-tag (STag^{40}), or EmptyElemTag^{44}.

Attribute definition

A single attribute definition, including its name, its requirement status and possibly its default and allowed values.

See also [AttDef{53} (Attribute Definition)]

attribute list declaration

See [AttlistDecl{52} (Attribute list Declaration) The markup used to define attributes and assign them to a specific element. Although there may be more than one attribute list declaration for an element, for compatibility with SGML only one should be used.]

attribute name

The name of a defined attribute.

attribute type

An attribute is assigned to a category, such as 'CDATA' (character data) or 'ID' (unique identifier).

See also [AttType{54} (Attribute Type)]

attribute value

The value of a specific attribute instance.

See also [AttValue{10} (Attribute Value)]

AttType^{54} (Attribute Type)

A category of attribute, applied to a specific attribute. Whenever that attribute is used, its value is simply restricted in some way ('NMTOKEN', 'NMTOKENS' and enumerated values) or may also be deemed to have some special significance ('', 'IDREF', 'IDREFS', 'ENTITY', 'ENTITIES' and 'NOTATION').

AttValue^{10} (Attribute Value)

The value of an attribute as its appears in the element start-tag.

AVI (Audio Video Interleave)

Full motion video format developed by Microsoft.

axis

In XPath, a direction through the document structure. Ascendents, descendants, parent, children, preceding siblings, following siblings, preceding elements (to the start of the document) following elements (to the end of the document), and attribute lists are all examples. Used in expressions with a keyword and a node filter, separated by double colons, '::', as in 'parent::chapter'.