Code (metadata)
Encyclopedia
In metadata
, the representation term
code refers to, and is used in the name of, data element
s whose allowable values can be represented as enumerated lists. Each enumerated value is a string that for brevity represents a specific meaning. For example, for a PersonGenderCode the allowable code valid values might be "male", "female" or "unknown". To be compliant with ISO standards a value meaning or definition must also be associated with each code.
The ISO/IEC 11179
metadata registry standard defines code as a system of valid symbols that substitute for longer values.
In general, if the number of codes is small the list of valid codes and their definitions can be transmitted with a document that validates the data. Codes usually have a symbolic meaning that can be understood by a person.
One example code is a set of two letter state codes used in a US postal address. The code MN represents the state of Minnesota. Its equivalent ID using FIPS
standards is the number 27. The number 27 would be classified as having a representation term of type Identifier and have the representation suffix of ID.
Another example is the three-letter international airport
codes such as 'MSP' for the Minneapolis-St. Paul Airport. Although people use these codes to identify an airport, they would be classified as having a representation term of Code because they contain mnemonic information.
Sometimes identification systems are also called "codes" in common every-day language. For example people frequently refer to a location's "zip code". Because of the lack of symbolic meaning in a numeric value, zip codes would technically be classified under ISO guidelines as an identifier. For example in the NIEM and GJXDM
standards a zip code is called LocationPostalCodeID. The concept is Location, the property is PostalCode and the representation term is ID.
It is sometimes difficult to determine if a data element is a code or an identifier. In general identifiers are sequential numbers used to identify a specific item in an identification scheme
. If a data element has mnemonic information it is generally classified as a code.
If only two code values are needed, an indicator
(Boolean true/false) representation term can be used.
Metadata
The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
, the representation term
Representation term
A representation term is a word, or a combination of words, that semantically represent the data type of a data element. A representation term is commonly referred to as a class word by those familiar with data dictionaries...
code refers to, and is used in the name of, data element
Data element
In metadata, the term data element is an atomic unit of data that has precise meaning or precise semantics. A data element has:# An identification such as a data element name# A clear data element definition# One or more representation terms...
s whose allowable values can be represented as enumerated lists. Each enumerated value is a string that for brevity represents a specific meaning. For example, for a PersonGenderCode the allowable code valid values might be "male", "female" or "unknown". To be compliant with ISO standards a value meaning or definition must also be associated with each code.
The ISO/IEC 11179
ISO/IEC 11179
ISO/IEC 11179 is an international standard for representing metadata for an organization in a metadata registry.- Intended purpose :...
metadata registry standard defines code as a system of valid symbols that substitute for longer values.
In general, if the number of codes is small the list of valid codes and their definitions can be transmitted with a document that validates the data. Codes usually have a symbolic meaning that can be understood by a person.
One example code is a set of two letter state codes used in a US postal address. The code MN represents the state of Minnesota. Its equivalent ID using FIPS
FIPS state code
FIPS state codes were numeric and two-letter alphabetic codes defined in U.S. Federal Information Processing Standard Publication 5-2 to identify U.S. states and certain other associated areas...
standards is the number 27. The number 27 would be classified as having a representation term of type Identifier and have the representation suffix of ID.
Another example is the three-letter international airport
IATA airport code
An IATA airport code, also known an IATA location identifier, IATA station code or simply a location identifier, is a three-letter code designating many airports around the world, defined by the International Air Transport Association...
codes such as 'MSP' for the Minneapolis-St. Paul Airport. Although people use these codes to identify an airport, they would be classified as having a representation term of Code because they contain mnemonic information.
Sometimes identification systems are also called "codes" in common every-day language. For example people frequently refer to a location's "zip code". Because of the lack of symbolic meaning in a numeric value, zip codes would technically be classified under ISO guidelines as an identifier. For example in the NIEM and GJXDM
GJXDM
The Global Justice XML Data Model is a data reference model for the exchange of information within the justice and public safety communities...
standards a zip code is called LocationPostalCodeID. The concept is Location, the property is PostalCode and the representation term is ID.
It is sometimes difficult to determine if a data element is a code or an identifier. In general identifiers are sequential numbers used to identify a specific item in an identification scheme
Identification scheme
In metadata, an identification scheme is used to identify unique records in a set.If a data element is used to identify a record within a data set, the data element uses the Identifier representation term....
. If a data element has mnemonic information it is generally classified as a code.
If only two code values are needed, an indicator
Indicator (metadata)
In metadata an indicator is a Boolean value that may contain only the values true or false. The definition of an Indicator must include the meaning of a true value and should also include the meaning if the value is false....
(Boolean true/false) representation term can be used.
See also
- MetadataMetadataThe term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
- Metadata registryMetadata registryA metadata registry is a central location in an organization where metadata definitions are stored and maintained in a controlled method.-Use of Metadata Registries:...
- ISO/IEC 11179ISO/IEC 11179ISO/IEC 11179 is an international standard for representing metadata for an organization in a metadata registry.- Intended purpose :...
- Data elementData elementIn metadata, the term data element is an atomic unit of data that has precise meaning or precise semantics. A data element has:# An identification such as a data element name# A clear data element definition# One or more representation terms...
- Identifier (metadata)
- Indicator (metadata)Indicator (metadata)In metadata an indicator is a Boolean value that may contain only the values true or false. The definition of an Indicator must include the meaning of a true value and should also include the meaning if the value is false....
- Representation termRepresentation termA representation term is a word, or a combination of words, that semantically represent the data type of a data element. A representation term is commonly referred to as a class word by those familiar with data dictionaries...
- Representation classRepresentation classA representation term is a word, or a combination of words, used as part of a data element name. Representation class is sometimes used as a synonym for representation term....
- Federal Information Processing StandardFederal Information Processing StandardA Federal Information Processing Standard is a publicly announced standardization developed by the United States federal government for use in computer systems by all non-military government agencies and by government contractors, when properly invoked and tailored on a contract...