What it is
STANAG 6023 is a NATO Standardization Agreement, not a training curriculum in its own right. It is the mechanism by which participating nations commit to implement ATrainP-1, Edition D, the Allied publication that actually carries the training and education standard for peace support operations. Anyone looking for what the training itself covers needs ATrainP-1; this cover does not describe it.
Why the agreement exists
The STANAG states its aim as responding to interoperability requirements: a common training standard and "a common knowledge about tactics, techniques and procedures (TTP) particularly required for peace operations and not being basic soldier tasks", a common base for combined operations, and reduced friction and duplicated effort among NATO nations and operational partners in peace support operations.
What participating nations agree to
"Participating nations agree to implement the following standard": ATrainP-1, Edition D. Nations examine their own ratification of the STANAG and advise NATO's Standardization Office (NSO) of their implementation intentions, providing their actual implementation details. Those national decisions and responses are recorded in the NATO Standardization Document Database (NSDD). Partner nations sit outside this ratification process and are invited separately to adopt the standard.
Reporting, not certification
Once a nation has ratified, it implements ATrainP-1 "in accordance with their ratification responses" and is invited to report its effective implementation of the STANAG in the format set out in AAP-03. Partner nations report their adoption the same way. There is no accredited body, notified body or customer audit named anywhere in this cover: what exists is a reporting chain running from nations to the NSO, and a periodic review of the STANAG itself at least once every five years, with proposed changes routed through a standardization proposal to the tasking authority.
Where this sits among related documents
This edition (Edition 5, 14 March 2019) supersedes Edition 4. Alongside ATrainP-1, the cover lists STANAG 2606 (which covers ATP-3.2.1.1, guidance for tactical stability activities and tasks), STANAG 2181 (which covers AJP-3.4.1, Allied joint doctrine for the military contribution to peace support), and STANAG 2611 (which covers AJP-3.4.4, Allied joint doctrine for counter-insurgency). None of these are requirements this STANAG imposes; they are named as related reading. AAP-03 supplies the format nations use for the implementation and adoption reporting described above.