Allergen + sub-diet flags, nut-free, soy-free, gluten-free, how do you wire them?

Each allergen / sub-diet is a Magento product attribute, same shape as the cert system but used for filtering not certification. The flags I always wire in:

• Nut-free, critical for tree-nut allergy customers (cashew cheese, almond products are nut-based; many vegan customers have nut allergies).
• Soy-free, many plant-based meats are soy-heavy; soy-allergy customers need the filter.
• Gluten-free, certified GF (GFCO) where possible, badge it.
• Oat-free, yes, oat allergies exist. Surprise customers if you don’t flag it.
• Refined-sugar-free, for the whole-foods / sugar-conscious audience.
• Raw, paleo-compatible, keto-compatible, kosher, halal, surface where relevant.

Each attribute renders as:

• Badge on PDP + category cards
• Filter facet in layered nav (combinable, “vegan AND nut-free AND gluten-free” is the #1 combo on most vegan DTC stores in my analytics)
• Schema.org suitableForDiet with values like VeganDiet, GlutenFreeDiet
• Highlight in the cart so allergic customers see the confirmation at checkout

Get this right and category-page bounce rate drops 20%+ because customers can self-filter to safety in one click. Get it wrong and you’ll spend support hours on “does this contain X?” queries.