Scope: Ski boots, ski bindings, snowboard boots, and snowboard bindings (skis and snowboards themselves are the sibling leaf "skis").

Seed:
1. The generic trap is the flex-index number everyone prints; it isn't standardized between brands. The real split is the boot's sole standard / binding type pairing (ISO 5355 alpine vs ISO 9523/GripWalk touring vs tech-pin inserts) — that's what actually gates whether the gear releases correctly together.
2. A climber who thinks in certification would notice that snowboard bindings carry no release certification at all, and that even ski-touring tech bindings split: only heel-elastic/frame ones are commonly tested to ISO 13992, so a lightweight tech binding's DIN-like number may never have been independently tested.

Sources:
[wikipedia_ski_binding] https://en.wikipedia.org/wiki/Ski_binding — DIN value, ISO 5355/9523 pivot locations, tech vs frame terms — fetched (Special:Export wikitext)
[wikipedia_ski_boot] https://en.wikipedia.org/wiki/Ski_boot — Mondopoint, ISO 5355, GripWalk/ISO 23223, walk mode, buckle/BOA — fetched (Special:Export wikitext)
[wikipedia_snowboard] https://en.wikipedia.org/wiki/Snowboard — boot types, lacing, binding types, highback F1-F5, mounting — fetched (Special:Export wikitext)
[evo_ski_boot_guide] https://www.evo.com/guides/how-to-choose-ski-boots — flex index ranges, last width mm, walk mode, heat-moldable liners/shells — fetched, grepped
[evo_din_chart] https://www.evo.com/blogs/guides/how-to-choose-ski-bindings-and-din-setting-chart — DIN chart 0.5-18, brake width rule, ISO 9462 — fetched, grepped
[evo_sole_compat] https://www.evo.com/blogs/guides/ski-boot-sole-bidning-compatibility — 5 sole standards, AFD/WTR, ISO 9462/13992 binding testing split — fetched, grepped
[evo_at_bindings] https://www.evo.com/blogs/guides/how-to-buy-alpine-touring-bindings — tech binding pin mechanism, ISO 13992 — fetched, grepped
[evo_snowboard_boot_fit] https://www.evo.com/blogs/guides/snowboard-boot-fit-flex-compatibility — 1-10 flex scale and bands, lacing options — fetched, grepped
[evo_quick_entry] https://www.evo.com/blogs/guides/quick-entry-snowboard-bindings — Step On/FASE/Supermatic quick-entry — fetched, grepped
[gearjunkie_backcountry_bindings] https://gearjunkie.com/winter/best-backcountry-ski-bindings — per-model DIN sub-ranges, uncertified release values, hybrid multi-norm — fetched, grepped
[burton_boots] https://www.burton.com/us/en/c/snowboard-boots — current lacing/liner marketing terms — fetched, grepped (JS-heavy, thin)
[burton_stepon_faq] https://www.burton.com/us/en/stepon-faq — Step On mechanism, Re:Flex mounting — fetched, grepped (JS-heavy, thin)

Branches:
equipment_type -> ski_boots/ski_bindings/snowboard_boots/snowboard_bindings: each type's spec sheet is unrelated (wikipedia_ski_binding, wikipedia_snowboard).
use_context -> backcountry_touring: swaps sole standard and binding type toward touring/tech, per evo_at_bindings and wikipedia_ski_boot's walk-mode description.

Noise (spec rows left out):
- boot_sole_length (BSL, mm) — a per-pair technician measurement used to mount/adjust bindings, not a buyer-facing comparison attribute; covered in evo_din_chart.
- brake_width (mm) — not an independent buyer choice but a fitting constraint tied to the ski's waist width (a sibling leaf's attribute); captured instead as a judgement.
- snowboard binding angle / stance width — a setup preference adjusted after purchase on any binding, not a product spec that differentiates listings.
- cross-country/Nordic/telemark boots and bindings (NNN, SNS, 75mm Nordic Norm, NTN) — out of scope for this leaf's alpine/snowboard framing; would need its own facet set if added later.

Corrections (2026-10-26):
- Fixed `boot_flex_rating.why_experts_care`'s bands to evo_ski_boot_guide's actual men's/women's table (110-120 stiff, not 105-130); was contradicting the source's own detailed table.
- Added `moldable` value to `snowboard_boot_liner_type` for evo_snowboard_boot_fit's middle liner tier, and added that source to its evidence.
- Relabeled `ski_binding_release_din.source` from `researched` to `listing` per its own backfill_note (printed directly on most listings, no bucketing).
- Dropped `gearjunkie_backcountry_bindings` from `ski_binding_release_din`'s evidence — it only supports per-model DIN sub-ranges, not the 0.5-18 industry span; no second source for that span was found, so the facet is now honestly single-sourced to evo_din_chart.
- Added vocabulary entries for "Flex index" (ski boot), "Flex rating (snowboard)", and "MNC (Multi-Norm Compatible)", confirmed against evo_sole_compat's "MNC or MN Bindings" text.