# Reserved prefix protection for metafields and metaobjects — Shopify developer changelog
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## Reserved prefix protection for metafields and metaobjects

Starting today, [reserved prefixes](https://shopify.dev/docs/apps/build/custom-data/ownership#reserved-prefixes) have been widened to include any phrase. You can no longer make any metafield namespace or metaobject type that includes `--` (e.g., `foo--` , `foo--bar` ). This only affects new metafield and metaobject definitions; existing definitions will continue to work as before. This change is intended to reserve the `--` format for platform defined features such as `shopify--{standard}` and `app--{your-app-id}`.

*Published: February 19, 2025*
Tags: API, Update
Link: https://shopify.dev/changelog/reserved-prefix-protection-for-metafields-and-metaobjects

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