Added automatic builds
Each day a ZIP-file is created via cron.
The builds consist of XMI, XSD, DocBook, PDF and graphs in dot, svg and png.
Added basic validation for names
installed module for validation, some rules for object and package names have been defined.
Added help for creating and managing the model
Guidelines for naming and propeties.
Added stage-tagging for objects
Re-arranged "Status" and added field for Stage, filter added on objects page.
Changes for Datatype
Datatype taxonomy is replaced by a datatype content type, to create a new one go to /node/add/datatype. You can specify basic documentation of the datatype and specify enumerated values. A datatype must be placed in a package.

Welcome to the development platform for the next generation of DDI

The DDI Alliance is building a new model-based specification, for more information on the background to this see, the process and what we hope to achieve see the DDI Alliance website at

A site to hold discussions and further ongoing discussion is at


PurposeControlled Vocabularies in DDI4
The representation of a controlled vocabulary in DDI4 consists of three classes:
ControlledVocabulary – The structured collection of vocabulary entries
VocabularyEntry – Assigns a definition to a term
VocabularyRelationStructure – Allows for the description of a complex structure among the terms, such as a hierarchy


TypedString combines a typeOfContent with a content defined as a simple string. May be used wherever a simple string needs to support a type definition to clarify its content



Restriction: The chaining goes back to the InstanceVariable. Relationships to higher level conceptual content has not been included


To review the conceptual concept structures and to manage concept systems (other than statistical classifications). The coverage go down to a RepresentedVariable. InstanceVariable has been included in the collection for use as a member of a VariableCollection. However it does not go into the detailed content of an InstanceVariable.

InstanceVariable has been included for the sole purpose of membership in a VariableCollection. The classes required to completely describe an InstanceVariable have not been included.


Support the description of business processing such as data transformation, harmonization, ingest processing, creation of OAIS packages, etc.

Restriction: Study has been included in the view so that it can be included in describing a Data Pipeline. The relationships of Study are not supported by this view.


A Business Algorithm is used to express the generalized function of the Business Process.
The underlying properties of the algorithm or method rather than the specifics of any particular implementation. In short a description of the method in its simplest and most general representation.


Custom Metadata allows for the creation of specialized key value pairs and values with DDI classes. This view was created to demonstrate the use of this set of classes.

The DDI4 CustomMetadataView allows for the definition of a set of keys and their interrelationships. This structure can be shared and reused by a community.
These keys can be used in key-value pairs to enter metadata that is more actionable than would be if an uncontrolled set of keys were employed.


NonNegativeInteger is derived from an iteger by disallowing values less than 0. The value space of non-negative integer is the infinite set {0,1,2,...}.

The formal definition of NonNegativeInteger is at:


This package contains Enumerations and classes described with Regular Expressions
Enumerations = datatypes created to support a fixed enumeration or controlled vocabulary which are defined and managed by DDI internal to the model
Regular Expressions = datatypes defined by pattern defined as a regular expression

All enumerations should be expressed in UpperCamelCase


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