What it is
A recommendation, not an obligation
STANREC 4821 is a NATO Standardization Recommendation on the Load Effects Assessment Program (LEAP). As with every STANREC, the distinction that matters most is in its name: unlike a STANAG, it does not commit a nation to ratify anything. NATO's own text is explicit that "Nations are invited to use the Allied standard(s) covered by the STANREC and to provide feedback to the NSO on the use of the covered Allied standard(s)" - an invitation, not a ratification obligation. Nothing in this document creates a duty for a supplier to sign up to directly.
What it recommends
The document's aim is to "list recommended practices regarding: a test method measuring soldier mobility to assist in the development, acquisition and evaluation of the impact of Dismounted Soldier Systems (DSS) equipment." Its recommendation is a single Allied Publication: AEP-4821, Edition A, the document that actually contains the load effects test method. The document names no other related reading and supersedes nothing - this is a clean first recommendation, not a revision of an earlier one.
Where the actual requirements live
STANREC 4821 has no clauses of its own to audit against. Nations and NATO bodies are asked to "provide feedback to the NSO on the use of Allied standards covered by a STANREC," and the document itself "is to be reviewed in accordance with AAP-03," with the result recorded in the NATO Standardization Document Database. That review checks the recommendation's own currency, not an organisation, and the test method itself, the part an evaluator would actually run, sits inside AEP-4821, not here.
Who supervises it
This STANREC is supervised under the authority of the NATO Army Armaments Group (NAAG), through its Land Capability Group on Dismounted Soldier Systems (LCGDSS), and comments on it go to the NATO Standardization Office (NSO). It is "a NATO non-classified document to be handled in accordance with C-M(2002)60."