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## Cornerstone 6.21.0

Cornerstone 6.21.0 introduces featured promotion callouts across product listing pages and the product page, expands and refines backorder messaging on the product page and account order pages, and includes a cart layout fix.

### Featured promotions

* **Featured promotion callouts** — Displays featured promotion callouts on product listing pages (product cards and list view) and the product page, controlled by the new `show_featured_promotions` theme setting and populated from the `featured_promotions` context

### Backorder messaging

* **Backorder prompts on order details** — Shows backorder prompts on the account order details page for both the parent product (under the product title) and each picklist option, mirroring the PDP backorder display
* **Default backorder message fallback** — Falls back to the store's default backorder message on the PDP when a product has no explicit message assignment or references a deleted message
* **Independent backorder message setting** — Decouples "Show backorder message" from "Qty on Backorder" so each setting works independently on the PDP

### Cart improvements

* **Shipping expectation message alignment** — Fixes the alignment of the shipping expectation message on the cart page