Project news

Conformance Targets Attribute Specification (CTAS) v3.0 Project Specification 01 approved by the NIEMOpen OP

CTAS v3.0 is ready for testing and implementation

OASIS is pleased to announce that Conformance Targets Attribute Specification (CTAS) Version 3.0 from the NIEMOpen Open Project [1] has been approved as an OASIS Project Specification.

NIEM is a framework for exchanging information between public and private sector organizations. The framework includes a reference data model for objects, properties, and relationships as well as a set of technical specifications for using and extending the data model in information exchanges. NIEM promotes scalability and reusability of messages between information systems which allows organizations to share data and information more efficiently.

This document specifies an XML attribute that may occur within XML documents to establish a claim that the document conforms to a set of conformance targets. Each conformance target is identified by an internationalized resource identifier, which is defined by its relevant specification.

This Project Specification is an OASIS deliverable, completed and approved by the OP’s Project Governing Board and fully ready for testing and implementation. The applicable open source licenses can be found in the project’s administrative repository at

The specification and related files are available at:

Conformance Targets Attribute Specification (CTAS) Version 3.0
Project Specification 01
22 February 2023

HTML (Authoritative):
XML schema:

Distribution ZIP file

For your convenience, OASIS provides a complete package of the specification and related files in a ZIP distribution file. You can download the ZIP file at:

Members of the NIEMOpen OP Project Governing Board approved this specification by Special Majority Vote [2] as required by the Open Project rules [3].

Our congratulations to the participants and contributors in the NIEMOpen Open Project on their achieving this milestone.

Additional references

[1] NIEMOpen Open Project

[2] Approval ballot: