Data element

In metadata, the term data element is an atomic unit of data that has precise meaning or precise semantics. Data elements usage can be discovered by inspection of software applications or application data files through a process of manual or automated Application Discovery and Understanding. Once data elements are discovered they can be registered in a metadata registry. In the areas of databases and data systems more generally a data element is a concept forming part of a data model. As an element of data representation, a collection of data elements forms a data structure.

Properties

A data element has:

1. An identification such as a data element name
2. A clear data element definition
3. One or more representation terms
4. Optional enumerated values Code (metadata)
5. A list of synonyms to data elements in other metadata registries Synonym ring

Name

A data element name is a name given to a data element in, for example, a data dictionary or metadata registry. In a formal data dictionary, there is often a requirement that no two data elements may have the same name, to allow the data element name to become an identifier, though some data dictionaries may provide ways to qualify the name in some way, for example by the application system or other context in which it occurs.

In a database driven data dictionary, the fully qualified data element name may become the primary key, or an alternate key, of a Data Elements table of the data dictionary.

The data element name typically conforms to ISO/IEC 11179 metadata registry naming conventions and has at least three parts:

• Object, Property and Representation term.

Many standards require the use of Upper camel case to differentiate the components of a data element name. This is the standard used by ebXML, GJXDM and NIEM.

Example of ISO/IEC 11179 name in XML

Users frequently encounter ISO/IEC 11179 when they are exposed to XML Data Element names that have a multi-part Camel Case format:

Object [Qualifier] Property RepresentationTerm

The specification also includes normative documentation in appendices.

For example, the XML element for a person's given (first) name would be expressed as:

<PersonGivenName>John</PersonGivenName>

Where Person is the Object=Person, Property=Given and Representation term="Name". In this case the optional qualifier is not used, in spite of being implicit in the data element name. This requires knowledge based on data element name, rather than use of structured data.

In telecommunications

In telecommunications, the term data element has the following components:

1. A named unit of data that, in some contexts, is considered indivisible and in other contexts may consist of data items.
2. A named identifier of each of the entities and their attributes that are represented in a database.
3. A basic unit of information built on standard structures having a unique meaning and distinct units or values.
4. In electronic record-keeping, a combination of characters or bytes referring to one separate item of information, such as name, address, or age.

In practice

In practice, data elements (fields, columns, attributes, etc.) are sometimes "overloaded", meaning a given data element will have multiple potential meanings. While a known bad practice, overloading is nevertheless a very real factor or barrier to understanding what a system is doing.

See also

• Application Discovery and Understanding
• Data element definition
• Data dictionary
• Data hierarchy
• ISO/IEC 11179 metadata registry specification
• Metadata
• Representation term
• Universal Data Element Framework
• Data collection system
• Semantic spectrum

References

•  This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22.
•  This article incorporates public domain material from Dictionary of Military and Associated Terms. United States Department of Defense.

Bibliography

• ISO/IEC 11179-5:2015 Metadata registries (MDR) - Part 5: Naming and identification principles
• "XML Developer's Guide V1.1 – 1 May 2002". DON XML Working Group. 2002-05-01. Retrieved 24 June 2025.

External links

• Federal XML Developer's Guide
• ISO/IEC 11179 Standards (see ISO/IEC 11179-3:2003 clause 3.3.36)