What it is
A recommendation, not an obligation
STANREC 4815 is a NATO Standardization Recommendation covering NATO's modelling and simulation (M&S) domain. The distinction that matters most is in its name: unlike a STANAG, a STANREC 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 stated aim is "selection and use of standards to promote interoperability, best practice and reuse" in the M&S domain. It recommends one standard: AMSP-01, Edition E. Alongside it, the document names two related references without saying either binds anything here: STANAG 5524, which covers the NATO Interoperability Standards and Profiles (NISP), and ADatP-34.
A second edition of the same recommendation
This edition "supersedes the following document: STANREC 4815, Edition 1, dated 23 February 2018". It was promulgated on 6 September 2021. The recommendation itself, in other words, has been current NATO practice in one form or another for several years; this is a refresh of the standard it points at, not a first issue.
Where the actual requirements live
STANREC 4815 has no clauses of its own to audit against. Its content is a promulgation letter and a short recommendation, five pages long, and the testable requirements, if any, sit inside AMSP-01, the standard it names, not in this document. The document is reviewed periodically in line with AAP-03, with the result recorded in the NATO Standardization Document Database; that review checks the recommendation's own currency, not an organisation or a simulation product.