View source for Category Scheme V10

[[Category:SDMX Structures]]
[[Category:SDMX 3.0 Structures]]
=Overview=
A Category Scheme is a container for [[Category|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==
{| class="wikitable"
! scope=row style="text-align: left;" | Structure Type 
| Standard SDMX Structural Metadata Artefact
|-
! scope=row style="text-align: left;"  | Maintainable
| [[Maintainable|Yes]]
|-
! scope=row style="text-align: left;"  | Identifiable
| [[Identifiable|Yes]]
|-
! scope=row style="text-align: left;"  | Item Scheme
| [[Item_Scheme|Yes]]
|-
! scope=row style="text-align: left;"  | SDMX Information Model Versions 
| 2.0, 2.1, 3.0
|-
! scope=row style="text-align: left;"  | URN - CategoryScheme namespace
| <nowiki>urn:sdmx:org.sdmx.infomodel.categorycheme.CategoryScheme</nowiki>
|-
! scope=row style="text-align: left;"  | URN - categorisation namespace
| <nowiki>urn:sdmx:org.sdmx.infomodel.categorycheme.Categorisation</nowiki>
|}

==Context within the SDMX 2.1 Information Model==
[[File:L_CategoryScheme.png|Category Scheme|600px]]

=Usage=
[[Category|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 https://registry.sdmx.org/items/conceptscheme.html.

More information on [[Category_Schemes_and_Categorisations|Category schemes]] can be found in this [https://fmrwiki.sdmxcloud.org/Category_Schemes_and_Categorisations article.]

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

{| class="wikitable"
|-
! Agency !! Category Scheme ID ID !! Description !! SDMX-ML
|-
| ESTAT || ESA2010TP || ESA 2010 - Transmission programme || [	https://registry.sdmx.org/ws/public/sdmxapi/rest/categoryscheme/ESTAT/ESA2010TP/1.0 SDMX-ML]
|-
| SDMX || STAT_SUBJECT_MATTER || SDMX Statistical Subject-Matter Domains || [	https://registry.sdmx.org/ws/public/sdmxapi/rest/categoryscheme/SDMX/STAT_SUBJECT_MATTER/1.0 SDMX-ML]
|}

=Flat Category Schemes=
<p>Flat Category Schemes are simple lists of codes with no explicit or implied relationships or hierarchies.</p>

<p> Example Category Scheme</p>
{| class="wikitable"
|-
! 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=
<p>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.</p>

<p>Example: SDMX STAT_SUBJECT_MATTER</p>

<p>
{| class="wikitable"
|-
! Code ID !! Code Name !! Parent
|-
| DEMO_SOCIAL_STAT || Demographic and social statistics || (none)
|-
| POP_MIGRATION || Population and migration || DEMO_SOCIAL_STAT
|-
| LABOUR || Labour || DEMO_SOCIAL_STAT
|-
| EDUCATION || Education || DEMO_SOCIAL_STAT
|-
|}
A Category can only have one parent meaning that it can only appear once in a simple Category Scheme hierarchy.