The term cross-reference (abbreviation: xref) can refer to either:
* An instance within a
document
A document is a written, drawn, presented, or memorialized representation of thought, often the manifestation of non-fictional, as well as fictional, content. The word originates from the Latin ''Documentum'', which denotes a "teaching" or ...
which refers to related information elsewhere in the same document. In both printed and online dictionaries cross-references are important because they form a network structure of relations existing between different parts of data, dictionary-internal as well as dictionary external.
* In an
index
Index (or its plural form indices) may refer to:
Arts, entertainment, and media Fictional entities
* Index (''A Certain Magical Index''), a character in the light novel series ''A Certain Magical Index''
* The Index, an item on a Halo megastru ...
, a cross-reference is often denoted by ''See also''. For example, under the term ''Albert Einstein'' in the index of a book about Nobel Laureates, there may be the cross-reference ''See also: Einstein, Albert''.
* In
hypertext
Hypertext is E-text, text displayed on a computer display or other electronic devices with references (hyperlinks) to other text that the reader can immediately access. Hypertext documents are interconnected by hyperlinks, which are typi ...
, cross-referencing is maintained to a document with either in-context (XRIC) or out-of-context (''XROC'') cross-referencing. These are similar to
KWIC and KWOC.
* In programming, "cross-referencing" means the listing of every file name and line number where a given
named identifier occurs within the program's
source tree
In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the wo ...
.
* In a
relational database management system
A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relatio ...
, a table can have an xref as prefix or suffix to indicate it is a
cross-reference table
An associative entity is a term used in relational and entity–relationship theory. A relational database requires the implementation of a base relation (or base table) to resolve many-to-many relationships. A base relation representing this ...
that joins two or more tables together via
primary key
In the relational model of databases, a primary key is a ''specific choice'' of a ''minimal'' set of attributes (Column (database), columns) that uniquely specify a tuple (Row (database), row) in a Relation (database), relation (Table (database), t ...
.
Structure
In a document, especially those authored in a
content management system
A content management system (CMS) is computer software used to manage the creation and modification of digital content (content management).''Managing Enterprise Content: A Unified Content Strategy''. Ann Rockley, Pamela Kostur, Steve Manning. New ...
,
a cross-reference has two major aspects:
* A visible form that appears when the document is presented to the reader
* A technical mechanism that resides within the system
The visible form contains text, graphics, and other indications that:
* Enable the reader to follow the cross-reference to the referenced content
* May enable the reader to understand what is being referred to, or what to expect upon following the reference
* May present to the reader some information from the referenced content
The technical mechanism that resides within the system:
* Identifies what location is being referred to
* Permits the system to present appropriate referencing text when the location containing the reference is presented to a reader
* Permits the system to offer a control (such as a link) that a reader can use when the content is presented in electronic form to access the referenced content
Enhancing usability
If the cross-reference mechanism is well designed, the reader will be able to follow each cross-reference to the referenced content whether the content is presented in print or electronically.
An author working in a content management system is responsible for identifying subjects of interest that cross documents, and creating appropriate systems of cross-references to support readers who seek to understand those subjects.
For an individual cross-reference, an author should ensure that location and content of the target of the cross-reference are clearly identified, and the reader can easily determine how to follow the cross-reference in each medium in which publication is supported.
Content strategy Content strategy is the planning, development, and management of content—written or in other media. The term has been particularly common in web development since the late 1990s. It is a recognized field in user experience design, and it also dra ...
practitioners (known as content strategists) specialize in planning content to meet business needs, taking into account the processes for creating and maintaining the content, and the systems that support the content.
See also
*
Credo Reference
Credo Reference or Credo (formerly Xrefer) is an American company that offers online reference content by subscription and partners with libraries to develop information-literacy programs or produce library marketing plans and materials.Swoger, B ...
References
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