properties /facet

THE FORMULATION FAMILY OF THE FRICTION COMPOUND — ceramic, semi-metallic, low-metallic, non-asbestos organic or sintered metallic. IT IS ITS OWN PROPERTY AND NOT THE SPINE'S `material`, and the question was put by the queue itself, so here is the answer with its evidence. First, ONE PART ANSWERS BOTH AT ONCE AND ANSWERS THEM DIFFERENTLY. A disc pad is two materials in one article: Bosch publishes a `powder-coated backing plate` of steel carrying a friction compound that is `platform-specific ceramic, semi-metallic and non-asbestos organic (NAO)`. The spine's `material` is cardinality-many and unordered, so folding the compound into it would produce the bag {steel, ceramic} with nothing to say which is the plate and which is the lining — a real loss of fidelity, not a notational one. Second, THE WORDS ARE HOMONYMS, NOT SHARED FACTS [A2]. `MaterialTypes` already holds `ceramic`, meaning the fired substance a mug is made of; a ceramic brake pad is a resin-bound composite that merely contains ceramic fibre, and Brembo's own published claim for its Prime Ceramic range is comparative — `less metal in its compound` — which is a statement about proportions in a mixture, not about what the thing is made of. Reusing the token would let a shelf match a ceramic pad to a ceramic bowl. Third, THREE OF THE FIVE VALUES ARE NOT SUBSTANCES AT ALL. `semi-metallic`, `low-metallic` and `non-asbestos organic` name proportions and exclusions in a recipe; there is no substance called semi-metallic. So a separate vocabulary is not padding but the only honest home. This is the same ruling b155 made for `electrode_material` and one step further: b155 kept `MaterialTypes` because an iridium electrode really is iridium, and noted the pool's standing rule that a named part's material is its own fact. Here the named part's material is its own fact AND its own vocabulary. The spine's `material` stays exactly where it was and carries the backing plate. RECORDED SO THE ARGUMENT NEED NOT BE MADE A FIFTH TIME [L10]: `ceramic` here is the friction compound class, not the substance — `val_MaterialTypes_ceramic` is what a bowl and a plug insulator are made of, while a ceramic brake pad is an organic binder matrix with ceramic fibres and no bulk ceramic. Same word, two concepts, two codes. And a pad answers both slots at once with a steel plate and a resin compound, which one `material [many]` with no qualifier cannot tell apart — the very thing `filter_media`'s definition already records for the WIX 51521.