What it is
A recommendation, not an obligation
STANREC 4661 is a NATO Standardization Recommendation on exchanging technical and logistic data during a product's life cycle support. 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 aim is "the consistent selection of standards to be used for the realization of standardized, generic, centralized and automated interfaces allowing the exchange of technical and logistic data during the product life cycle support." Its recommendation leads with ALP-20, Edition A, and adds a set of civil and industry standards: the ASD/AIA/ATA suite of S-series specifications for Integrated Logistic Support and In-Service Support (SX001G, SX002D, SX000i, S1000D, S2000M, S3000L, S4000P, S5000F and S6000T), ISO 10303-239 on product data representation and exchange, ISO 8000 on data quality, and ISO 22745 on open technical dictionaries for master data. None of these are explained further in the document itself; the point of STANREC 4661 is to name them, not to reproduce them.
Once a STANAG, now a recommendation
This edition supersedes STANAG 4661, Edition 1, dated 20 February 2008. The change of document type between editions is worth noting on its own: what nations once ratified as an agreement, they are now only invited to use. A reader who assumes the current STANREC carries the same weight as the STANAG it replaced would be assuming the wrong thing.
Where the actual requirements live
STANREC 4661 has no clauses of its own to audit against. Its "other related documents" separately name STANAG 4728 (System Life Cycle Management, alongside AAP-20 and AAP-48) and STANREC 4808 (Engineering in NATO Programmes, alongside AEP-67 and ALP-10) - adjacent reading, not content this recommendation depends on. The document is reviewed periodically in accordance with AAP-03, with the result recorded in the NATO Standardization Document Database; that review is the only ongoing mechanism the document names, and it checks the document's own currency, not an organisation.