Changes for page SDMX 3.1 Standards. Section 1. Framework

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@@ -95,7 +95,7 @@
  * Support for [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] list extension and discriminated union of [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] lists
  * Improvements to structure mapping
  * Improvements to [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] [[hierarchies>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] for data discovery
--* Improvements to [[constraints>>doc:sdmx:Glossary 2\.1.Constraint.WebHome]]
++* Improvements to constraints
  (% class="wikigeneratedid" id="HVersioningofStructuralMetadataArtefacts" %)
  **Versioning of Structural Metadata Artefacts**
@@ -139,14 +139,14 @@
  (% class="wikigeneratedid" id="HInformationModel-1" %)
  **Information Model**
--* Addition of [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] Constraint property to a [[Dataflow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]]
++* Addition of [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] (% style="color:#e74c3c" %)Constraint(%%) property to a [[Dataflow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]]
  * Addition of evolving structure property to a [[Data Structure Definition>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]]
--* Remove version property on [[Categorisation>>doc:sdmx:Glossary 2\.1.Categorisation.WebHome]]
--* Simplification of [[Constraints>>doc:sdmx:Glossary 2\.1.Constraint.WebHome]]
++* Remove (% style="color:#e74c3c" %)version(%%) property on [[Categorisation>>doc:sdmx:Glossary 2\.1.Categorisation.WebHome]]
++* Simplification of (% style="color:#e74c3c" %)Constraints
  ** Removal of Advanced [[Release Calendar>>doc:sdmx:Glossary 2\.1.Release policy - release calendar.WebHome]]
--** Removal of Role, Data [[Constraints>>doc:sdmx:Glossary 2\.1.Constraint.WebHome]] only restrict data that can be reported
--** Restrict [[constraint>>doc:sdmx:Glossary 2\.1.Constraint.WebHome]] targets to Identifiable structures (not URLs)
--** Addition of Availability [[Constraint>>doc:sdmx:Glossary 2\.1.Constraint.WebHome]] to define actual data
++** Removal of Role, Data (% style="color:#e74c3c" %)Constraints(%%) only restrict data that can be reported
++** Restrict (% style="color:#e74c3c" %)constraint(%%) targets to Identifiable structures (not URLs)
++** Addition of Availability (% style="color:#e74c3c" %)Constraint(%%) to define actual data
  (% class="wikigeneratedid" id="HDocumentation" %)
  **Documentation**
@@ -159,6 +159,7 @@
  == 3.1 Process Patterns ==
++
  [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] identifies three basic process patterns regarding the exchange of statistical data and metadata. These can be described as follows:
 . //**[[Bilateral exchange>>doc:sdmx:Glossary 2\.1.Bilateral exchange.WebHome]]**~:// All aspects of the exchange process are agreed between counterparties, including the mechanism for exchange of data and metadata, the formats, the frequency or schedule, and the mode used for communications regarding the exchange. This is perhaps the most common process pattern.
@@ -178,11 +178,11 @@
  == 3.3 Statistical Data and Metadata ==
--To avoid confusion about which "data" and "metadata" are the intended content of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] formats specified here, a statement of scope is offered. Statistical "data" are sets of often numeric observations which typically have time associated with them. They are associated with a set of metadata values, representing specific concepts, which act as identifiers and descriptors of the data. These metadata values and concepts can be understood as the named [[dimensions>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] of a multi-dimensional co-ordinate system, describing what is often called a "cube" of data.
++To avoid confusion about which "data" and "metadata" are the intended content of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] formats specified here, a statement of scope is offered. Statistical "data" are sets of often numeric observations which typically have time associated with them. They are associated with a set of metadata values, representing specific (% style="color:#e74c3c" %)concepts(%%), which act as identifiers and descriptors of the data. These metadata values and (% style="color:#e74c3c" %)concepts(%%) can be understood as the named [[dimensions>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] of a multi-dimensional co-ordinate system, describing what is often called a "cube" of data.
  [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] identifies a standard technique for modelling, expressing, and understanding the structure of this multi-dimensional "cube", allowing automated processing of data from a variety of sources. This approach is widely applicable across types of data and attempts to provide the simplest and most easily comprehensible technique that will support the exchange of this broad set of data and related metadata.
--The term "metadata" is very broad indeed. A distinction can be made between “structural” metadata – those concepts used in the description and identification of statistical data and metadata – and “reference” metadata – the larger set of concepts that describe and qualify statistical [[data sets>>doc:sdmx:Glossary 2\.1.Data set.WebHome]] and processing more generally, and which are often associated not with specific observations or [[series>>doc:sdmx:Glossary 2\.1.Series.WebHome]] of data, but with entire collections of data or even the institutions which provide that data.
++The term "metadata" is very broad indeed. A distinction can be made between “structural” metadata – those (% style="color:#e74c3c" %)concepts(%%) used in the description and identification of statistical data and metadata – and “reference” metadata – the larger set of (% style="color:#e74c3c" %)concepts(%%) that describe and qualify statistical [[data sets>>doc:sdmx:Glossary 2\.1.Data set.WebHome]] and processing more generally, and which are often associated not with specific observations or [[series>>doc:sdmx:Glossary 2\.1.Series.WebHome]] of data, but with entire collections of data or even the institutions which provide that data.
  The [[SDMX Information Model>>doc:sdmx:Glossary 2\.1.SDMX Information Model.WebHome]] provides for the structuring not only of data, but also of “reference” metadata. While these [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] structures exist independent of the data and its [[structural metadata>>doc:sdmx:Glossary 2\.1.Structural metadata.WebHome]], they are often linked. The [[SDMX Information Model>>doc:sdmx:Glossary 2\.1.SDMX Information Model.WebHome]] provides for the attachment of [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] to any part of the data or [[structural metadata>>doc:sdmx:Glossary 2\.1.Structural metadata.WebHome]], as well as for the reporting and exchange of the [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] and its structural descriptions. This function of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] standards supports many aspects of data quality initiatives, allowing as it does for the exchange of metadata in its broadest sense, of which quality-related metadata is a major part.
@@ -196,7 +196,7 @@
  This document specifies the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] standards designed to facilitate exchanges based on any of these process patterns, and shows how [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] offers advantages in all cases. It is possible to agree bilaterally to use a standard format (such as [[SDMX-ML>>doc:sdmx:Glossary 2\.1.SDMX-ML.WebHome]] or [[SDMX-JSON>>doc:sdmx:Glossary 2\.1.SDMX-JSON.WebHome]]); it is possible for data senders in a gateway process to use a standard format for [[data exchange>>doc:sdmx:Glossary 2\.1.Data exchange.WebHome]] with each other, or with any [[data providers>>doc:sdmx:Glossary 2\.1.Data provider.WebHome]] who agree to do so; it is possible to agree to use the full set of [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] standards to support a common data-sharing process of exchange, whether based on an [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]-conformant registry or some other architecture.
--The standards specified here specifically support a data-sharing process based on the use of central registry services. Registry services provide visibility into the data and metadata existing within the community, and support the access and use of this data and metadata by providing a set of triggers for automated processing. The data or metadata itself is not stored in a central registry – these services merely provide a useful set of metadata about the data (and additional metadata) in a known location, so that users/applications can easily locate and obtain whatever data and/or metadata is registered. The use of standards for all data, metadata, and the registry services themselves is ubiquitous, permitting a high level of automation within a data-sharing community.
++The standards specified here specifically support a data-sharing process based on the use of central registry services. Registry services provide visibility into the data and metadata existing within the community, and support the access and use of this data and metadata by providing a set of triggers for automated processing. The data or metadata itself is not stored in a central registry – these services merely provide a useful set of metadata about the data (and additional metadata) in a known location, so that users/applications can easily locate and obtain whatever data and/or metadata is registered. The use of standards for all data, metadata, and the registry services themselves is ubiquitous, permitting a high (% style="color:#e74c3c" %)level(%%) of automation within a data-sharing community.
  It should be pointed out that these different process models are not mutually exclusive – a single system capable of expressing data and metadata in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]-conformant formats could support all three scenarios. Different standards may be applicable to different processes (for example, many registry services interfaces are used only in a data-sharing scenario) but all have a common basis in a shared information model.
@@ -237,9 +237,10 @@
  * //**Organisation Scheme:**// Organisations and organisation structure can be defined in an Organisation Scheme. Specific Organisation Schemes exist for [[Maintenance Agency>>doc:sdmx:Glossary 2\.1.Maintenance agency.WebHome]], [[Data Provider>>doc:sdmx:Glossary 2\.1.Data provider.WebHome]], Metadata Provider, [[Data Consumer>>doc:sdmx:Glossary 2\.1.Data consumer.WebHome]], and Organisation [[Unit>>doc:sdmx:Glossary 2\.1.Statistical unit.WebHome]].
  * //**[[Category Scheme>>doc:sdmx:Glossary 2\.1.Category scheme.WebHome]] and [[Categorisation>>doc:sdmx:Glossary 2\.1.Categorisation.WebHome]]:**// [[Category schemes>>doc:sdmx:Glossary 2\.1.Category scheme.WebHome]] are made up of a [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] of [[categories>>doc:sdmx:Glossary 2\.1.Category.WebHome]], which in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] may include any type of useful [[classification>>doc:sdmx:Glossary 2\.1.Statistical Classification.WebHome]] for the organization of data and metadata. A [[Categorisation>>doc:sdmx:Glossary 2\.1.Categorisation.WebHome]] links a [[category>>doc:sdmx:Glossary 2\.1.Category.WebHome]] to an identifiable object. In this way sets of objects can be categorised. A statistical subjectmatter domain scheme is implemented in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] as a [[Category Scheme>>doc:sdmx:Glossary 2\.1.Category scheme.WebHome]].
  * //**[[Concept Scheme>>doc:sdmx:Glossary 2\.1.Concept scheme.WebHome]]:**// A [[concept scheme>>doc:sdmx:Glossary 2\.1.Concept scheme.WebHome]] is a maintained list of (% style="color:#e74c3c" %)concepts(%%) that are used in [[data structure definitions>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]] and [[metadata structure definitions>>doc:sdmx:Glossary 2\.1.Metadata structure definition.WebHome]]. There can be many such [[concept schemes>>doc:sdmx:Glossary 2\.1.Concept scheme.WebHome]]. A “core” [[representation>>doc:sdmx:Glossary 2\.1.Representation.WebHome]] of the (% style="color:#e74c3c" %)concept(%%) can be specified (e.g. a core [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] list, or other [[representation>>doc:sdmx:Glossary 2\.1.Representation.WebHome]] such as “date”). Note that this core [[representation>>doc:sdmx:Glossary 2\.1.Representation.WebHome]] can be overridden in the [[data structure definition>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]] or [[metadata structure definition>>doc:sdmx:Glossary 2\.1.Metadata structure definition.WebHome]] that uses the (% style="color:#e74c3c" %)concept(%%). Indeed, organisations wishing to remain with (% style="color:#e74c3c" %)version(%%) 1.0 key family schema specifications will continue to declare the [[representation>>doc:sdmx:Glossary 2\.1.Representation.WebHome]] in the key family definition.
++*
  * //**[[Metadata Set>>doc:sdmx:Glossary 2\.1.Metadata set.WebHome]]:**// A [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] set is a set of information pertaining to an object within the formal [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] view of statistical exchange: they may describe the maintainers of data or structural definitions; they may describe the schedule on which data is released; they may describe the flow of a single type of data over time; they may describe the quality of data, etc. In [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]], the creators of [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] may take whatever (% style="color:#e74c3c" %)concepts(%%) they are concerned with, or obliged to report, and provide a [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] set containing that information.
  * //**[[Metadata Structure Definition>>doc:sdmx:Glossary 2\.1.Metadata structure definition.WebHome]]:**// A [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] set also has a set of [[structural metadata>>doc:sdmx:Glossary 2\.1.Structural metadata.WebHome]] which describes how it is organized. This [[metadata set>>doc:sdmx:Glossary 2\.1.Metadata set.WebHome]] identifies what [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] (% style="color:#e74c3c" %)concepts(%%) are being reported, how these (% style="color:#e74c3c" %)concepts(%%) relate to each other (typically as [[hierarchies>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]]), what their presentational structure is, how they may be represented (as free text, as coded values, etc.), and with which formal [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] object types they are associated.
--* //**[[Dataflow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] Definition:**// In [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]], [[data sets>>doc:sdmx:Glossary 2\.1.Data set.WebHome]] are reported or disseminated according to a [[data flow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] definition. The [[data flow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] definition identifies the [[data structure definition>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]] and may be associated with one or more subject matter domains via a [[Categorisation>>doc:sdmx:Glossary 2\.1.Categorisation.WebHome]] (this facilitates the search for data according to organised [[category schemes>>doc:sdmx:Glossary 2\.1.Category scheme.WebHome]]). [[Constraints>>doc:sdmx:Glossary 2\.1.Constraint.WebHome]], in terms of reporting [[periodicity>>doc:sdmx:Glossary 2\.1.Frequency of observation.WebHome]] or sub set of possible keys that are allowed in a [[data set>>doc:sdmx:Glossary 2\.1.Data set.WebHome]], may be attached to the [[data flow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] definition.
++* //**[[Dataflow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] Definition:**// In [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]], [[data sets>>doc:sdmx:Glossary 2\.1.Data set.WebHome]] are reported or disseminated according to a [[data flow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] definition. The [[data flow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] definition identifies the [[data structure definition>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]] and may be associated with one or more subject matter domains via a [[Categorisation>>doc:sdmx:Glossary 2\.1.Categorisation.WebHome]] (this facilitates the search for data according to organised [[category schemes>>doc:sdmx:Glossary 2\.1.Category scheme.WebHome]]). (% style="color:#e74c3c" %)Constraints(%%), in terms of reporting [[periodicity>>doc:sdmx:Glossary 2\.1.Frequency of observation.WebHome]] or sub set of possible keys that are allowed in a [[data set>>doc:sdmx:Glossary 2\.1.Data set.WebHome]], may be attached to the [[data flow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] definition.
  * //**[[Metadataflow>>doc:sdmx:Glossary 2\.1.Metadataflow.WebHome]] Definition:**// A [[metadata flow>>doc:sdmx:Glossary 2\.1.Metadataflow.WebHome]] definition is very similar to a [[data flow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] definition, but describes, categorises, and constrains [[metadata sets>>doc:sdmx:Glossary 2\.1.Metadata set.WebHome]].
  * //**[[Data Provider>>doc:sdmx:Glossary 2\.1.Data provider.WebHome]]: **//An organization which produces data is termed a [[data provider>>doc:sdmx:Glossary 2\.1.Data provider.WebHome]].
  * //**Metadata Provider: **//An organization which produces [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] is termed a metadata provider.
@@ -295,7 +295,7 @@
  [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] recognizes that statistical data is structured; in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] this structure is termed a [[Data Structure Definition>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]]. “[[Data sets>>doc:sdmx:Glossary 2\.1.Data set.WebHome]]” are made up of one or more lower-(% style="color:#e74c3c" %)level(%%) “groups”, based on their degrees of similarity. Each group is in turn comprised of one or more “[[series>>doc:sdmx:Glossary 2\.1.Series.WebHome]]” of data. Each [[series>>doc:sdmx:Glossary 2\.1.Series.WebHome]] or section has a “key” - values for each of a cluster of (% style="color:#e74c3c" %)concepts(%%), also called "[[dimensions>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]]" - which identifies it, and one or more “observations”, which typically combine the time of the observation, and the value of the observation (e.g., measurement). Additionally, metadata may be attached at any (% style="color:#e74c3c" %)level(%%) of this structure as descriptive “[[attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]]”. [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] lists (enumerations) and other patterns for [[representation>>doc:sdmx:Glossary 2\.1.Representation.WebHome]] of data and metadata are also modelled.
--There is some similarity between “cube” structures commonly used to process statistical data, and the [[Data Structure Definition>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]] idea in the [[SDMX Information Model>>doc:sdmx:Glossary 2\.1.SDMX Information Model.WebHome]]. It is important to note that the data as structured according to the [[SDMX Information Model>>doc:sdmx:Glossary 2\.1.SDMX Information Model.WebHome]] is optimized for exchange, potentially with partners who may have no ability to process a “cube” of data coming from complex statistical systems. [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[time series>>doc:sdmx:Glossary 2\.1.Series.WebHome]] can be understood as “slices” of the cube. Such a slice is identified by its key. A "[[series>>doc:sdmx:Glossary 2\.1.Series.WebHome]]" key consists of the values for all [[dimensions>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] specified by the key family except time. Thus, it is possible to reconstruct and describe data cubes from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]-structured data, and to exchange such databases using the interfaces and formats provided for that purpose in the standard. Additional objects such as [[hierarchical code>>doc:sdmx:Glossary 2\.1.Hierarchical code.WebHome]] lists, [[constraints>>doc:sdmx:Glossary 2\.1.Constraint.WebHome]] and structure (% style="color:#e74c3c" %)maps(%%) make it possible to more fully model the structure of cubes.
++There is some similarity between “cube” structures commonly used to process statistical data, and the [[Data Structure Definition>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]] idea in the [[SDMX Information Model>>doc:sdmx:Glossary 2\.1.SDMX Information Model.WebHome]]. It is important to note that the data as structured according to the [[SDMX Information Model>>doc:sdmx:Glossary 2\.1.SDMX Information Model.WebHome]] is optimized for exchange, potentially with partners who may have no ability to process a “cube” of data coming from complex statistical systems. [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[time series>>doc:sdmx:Glossary 2\.1.Series.WebHome]] can be understood as “slices” of the cube. Such a slice is identified by its key. A "[[series>>doc:sdmx:Glossary 2\.1.Series.WebHome]]" key consists of the values for all [[dimensions>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] specified by the key family except time. Thus, it is possible to reconstruct and describe data cubes from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]-structured data, and to exchange such databases using the interfaces and formats provided for that purpose in the standard. Additional objects such as [[hierarchical code>>doc:sdmx:Glossary 2\.1.Hierarchical code.WebHome]] lists, (% style="color:#e74c3c" %)constraints(%%) and structure (% style="color:#e74c3c" %)maps(%%) make it possible to more fully model the structure of cubes.
  The information model also provides a view of [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]]: a mechanism for referencing the meaningful “objects” within the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] view of statistical exchange processes ([[data providers>>doc:sdmx:Glossary 2\.1.Data provider.WebHome]], structures, [[provisioning agreements>>doc:sdmx:Glossary 2\.1.Provision agreement.WebHome]], [[dataflows>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]], [[metadata flows>>doc:sdmx:Glossary 2\.1.Metadataflow.WebHome]], etc.) to which metadata is attached; a mechanism for describing a set of meaningful (% style="color:#e74c3c" %)concepts(%%), of organizing them into a presentational structure, and of indicating how their values are represented. This is based on a simple, hierarchical view of [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] which is common to many metadata systems and [[classification>>doc:sdmx:Glossary 2\.1.Statistical Classification.WebHome]]/categorization schemes. [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] provides a model (and XML and JSON formats) for both describing [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] structures, and of reporting [[reference metadata>>doc:sdmx:Glossary 2\.1.Reference metadata.WebHome]] according to those structures.