Category Scheme V11

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A Category Scheme is a container for Categories. An example of a category scheme is one which categorises data - sometimes known as a subject matter domain scheme or a data category scheme. The individual Categories can be associated to any set of identifiable Artifacts, known as a Categorisation.

Structure Properties

Structure Type Standard SDMX Structural Metadata Artefact
Maintainable Yes
Identifiable Yes
Item Scheme Yes
SDMX Information Model Versions 2.0, 2.1, 3.0
URN - CategoryScheme namespace urn:sdmx:org.sdmx.infomodel.categorycheme.CategoryScheme
URN - categorisation namespace urn:sdmx:org.sdmx.infomodel.categorycheme.Categorisation

Context within the SDMX 3.0 Information Model

Category Scheme


Categories are used within a Category Scheme and has the facility to have one or more child codes as well as being multi-lingual.

The SDMX Cross Domain Concept Scheme provides a range of standardised Concepts maintained by the SDMX Statistical Working Group (SWG) and can be viewed on the Global Registry site

More information on Category schemes can be found in this article.


Category Scheme IDs IDs are conventionally uppercase using underscores '_' as separators if required. Examples:

Agency Category Scheme ID ID Description SDMX-ML
ESTAT ESA2010TP ESA 2010 - Transmission programme [ SDMX-ML]
SDMX STAT_SUBJECT_MATTER SDMX Statistical Subject-Matter Domains [ SDMX-ML]

Flat Category Schemes

Flat Category Schemes are simple lists of codes with no explicit or implied relationships or hierarchies.

Example Category Scheme

Code ID Code Name Description
PUBLIC Public Sector Artifacts relating to the Public Sector.
PRIVATE Private Sector Artifacts relating to the Private Sector

Category Schemes with Simple Hierarchies

SDMX allows simple hierarchies to be defined within flat Concept Schemes by making a code the parent of codes that logically sit under it in the hierarchy.


Code ID Code Name Parent
DEMO_SOCIAL_STAT Demographic and social statistics (none)
POP_MIGRATION Population and migration DEMO_SOCIAL_STAT

A Category can only have one parent meaning that it can only appear once in a simple Category Scheme hierarchy.