properties /identity

A performance specification the fluid is published as meeting — the designation exactly as the maker prints it: 'API SN/CF', 'ACEA A3/B4', 'ILSAC GF-5', 'FMVSS 116 DOT 4', 'SAE J1704', 'ISO 4925 Class 4', 'ASTM D3306', 'MB-Approval 229.1', 'VW 502.00/505.00', 'DEXRON III', 'Type WS', 'JWS 3309', 'NS-3'. This is the fact a buyer actually looks up in the owner's manual, and it is what the trade's names for fluids are really made of. CARDINALITY MANY, proved on a real instance: MOTUL DOT 3&4 is ONE product published against FMVSS 116 DOT 3, FMVSS 116 DOT 4, ISO 4925 (3 and 4) and SAE J1703 at once, and TOTAL QUARTZ 5000 20W-50 carries ACEA A3/B3, API SL/CF, MB-Approval 229.1, PSA B71 2295 and VW 501.01/505.00. IT IS A DESIGNATION AND NEVER PROSE, and the field is not a free-text swamp: what goes in is the maker's printed designation and nothing else — never a sentence such as 'meets or exceeds the requirements of API SN', and NEVER AN ENGINE OR VEHICLE FAMILY. That last prohibition is load-bearing, because real approval blocks contain entries that are not specifications at all: TotalEnergies' GLACELF list carries 'CUMMINS ISBe engines' and 'MAN 4-stroke medium speed engines' beside genuine document numbers. Those are FITMENT — a cross-reference to a product the pool does not hold — and they belong downstream in `description` / `also_known_as` in the shop's own words, exactly as the 2026-08-25 amendment directs; admitting them here would build the vehicle-and-engine catalogue that amendment forbids, one value at a time, through the back door. A NOTE ON THE BINDING, recorded so a later session does not repeat the argument: this is bound to `LiteralText` and NOT to `LiteralCode`, for a hard reason — `LiteralCode`'s format law admits no whitespace at all, and eight of the nine commonest real designations contain a space ('API SN/CF', 'ACEA A3/B4', 'FMVSS 116 DOT 4', 'MB-Approval 229.1', 'Type WS', 'DEXRON III', 'ISO 4925 Class 4', 'JWS 3309'), so a code binding would force every one of them to be mis-transcribed. A dedicated designation format is a registry addition to the literal-format law and is queued as a follow-up. A LITERAL and not a token, deliberately and on the pool's own precedent: the list of manufacturer approvals is UNBOUNDED BY CONSTRUCTION — one TotalEnergies coolant sheet cites more than fifty, and a new one appears with every new engine — so the language names the slot and the data layer fills the designation, exactly as `trade_identifier` carries a part number under `identifier_scheme` and `un_number` carries a transport number. This is the same refusal the 2026-08-25 amendment made about vehicle catalogues, applied to a list that grows the same way. Contrast `viscosity_grade`, which IS a token: a grade is a place on a closed published scale, a specification is a document in an open library. DISTINCT from `certification` (compliance): a certification is a borne conformity mark drawn from a closed regulatory set (CE, UKCA, RoHS, ECE) that says the article may lawfully be sold; a specification says the fluid will WORK in a given machine, and it is the buying decision itself. DISTINCT from b153's `filtration_standard`, which names the TEST METHOD a filtration rating was measured under (ISO 16889, ISO 19438); this names a performance class the whole product is declared against. Concern identity, so NOT axis-eligible: a DOT 3 fluid and a DOT 4 fluid are two listings, not two cells of one buy box.