What it is
STANAG 2616 is a NATO Standardization Agreement, not a technical manual in its own right. Its entire operative content is one line: "Participating nations agree to implement" AJP-3.22, Edition A, the Allied joint doctrine for stability policing. The requirements a unit or a supplier actually works to live inside that Allied Publication; the STANAG is the ratified commitment that puts it into force.
Why the agreement exists
The document's own stated purpose is to close a gap in existing Allied doctrine: it says its doctrine "will contribute to fill a void in Allied Joint and Land Doctrine concerning the support and training of indigenous police forces which is not adequately addressed in current Counterinsurgency or Stability Activities doctrine." It also describes itself as the bridge "between the military component of stabilization mission and the follow on International police component," covering the handover from a military stabilization operation to a following international police presence.
Who it addresses
Two groups, in the document's own terms. First, the nations that ratify and implement it: the agreement "has been ratified by member nations, as reflected in the NATO Standardization Document Database (NSDD)," is "effective upon receipt and ready to be used by the implementing nations and NATO bodies," and partner nations are separately "invited to adopt" it. Second, the people the doctrine itself is written for: "commanders, staff and planners when designing and conducting crisis response operations and Stabilization & Reconstruction missions," mainly at the strategic and operational level, though the document says it "could also be used as a guide at the tactical level." It also states the doctrine is "equally applicable to operations conducted by a coalition of NATO with partner nations, non-NATO nations, and other organizations."
How a nation implements it, and how that is checked
The STANAG sets an operational test for implementation rather than a paperwork one: it is met when AJP-3.22 "has been included into national doctrine, promulgated nationally, included in training programmes and used within units earmarked for NATO." Nations report their implementation using the form in Annex H to AAP-03(J); partner nations report adoption using the form in Annex G to AAP-03(J). The document names no accredited body, no notified body and no audit against this STANAG; the checking it describes is nations reporting their own position to the NATO Standardization Office, not a third party assessing a supplier or a product.
The STANAG itself is reviewed "at least once every three years," and a nation or NATO body may propose changes "at any time" for the next review cycle, so the edition and the doctrine it points to can move.
What sits above and beside it
STANAG 2616 does not stand alone. Its own list of related documents places AJP-3.22 under the capstone AJP-01 and the conduct-of-operations doctrine in AJP-3 and AJP-3.2, and alongside doctrine on peace support (STANAG 2181, AJP-3.4.1), counterinsurgency (STANAG 2611, AJP-3.4.4), military police (STANAG 2296, AJP-3.2.3.3), tactical stability activities (STANAG 2606), tactical counterinsurgency activities (STANAG 2299), and civil-military cooperation (STANAG 2509, AJP-3.4.9). An organisation reading STANAG 2616 in isolation from that hierarchy will read it thin; the requirements live in the doctrine set it belongs to.