Kinds of NIEM Releases
A release is a versioned set of schemas and supporting artifacts published by the NIEM Management Office. Release schemas include NIEM Core, domains and code tables.
A Core Supplement is an incremental NIEM release that contains new or updated components for the NIEM Core namespace. These changes are published in separate schemas that can be used in addition to the original Core namespace. Core Supplements are used as a way of 'adjusting' Core content while it is locked between major releases.
A domain update is one or more schemas that constitute changes to a NIEM domain outside of the standard NIEM release cycle.
NIEM Release Artifacts
Each NIEM release comes bundled as a zip file containing schemas and other supporting files.
The image below shows the NIEM 4.0 release package on GitHub, with labels superimposed to point out the various artifacts.
NIEM XML Schemas
The NIEM release XML Schemas define the model content and the internal constructs needed to support the model. Schemas include Core, domains, codes, external standards, structures and appinfo.
The release README file is a text file that provides a high-level overview of the changes made in the release, and in particular any changes that might affect Core.
The NIEM model spreadsheet provides user documentation for the properties and types of Core and the domain namespaces.
The NIEM Code spreadsheet provides user documentation for the codes defined in a NIEM release.
Change Log Spreadsheet
The NIEM change log spreadsheet documents the changes between the given release and the previous one.
NIEM CSVs provide an alternate, non-authoritative representation of the NIEM schema content in a tabular format. They are made available to support developers who wish to import the model content without having to parse the schemas.