In addition to objects and properties, NIEM provides a few other ways to define the contents of a data exchange including:
- Associations - relationships between objects
- Augmentations - extensions (additional properties) added to an object
- Metadata - information about objects or properties (e.g. the source or security level of the information).
- Roles - Temporary functions played by objects (e.g. the person that is the subject of a case).