# Compatibility and Deprecations
This page exists so `mailglass_admin` HexDocs can surface the `1.x`
compatibility policy without duplicating the policy text inside the admin
package.
The canonical guide lives in the repo-root Mailglass docs:
- [`guides/compatibility-and-deprecations.md`](../../guides/compatibility-and-deprecations.md)
Use that guide for:
- the `stable lane` versus `compatibility lane` model
- patch, minor, and major release guarantees
- warnings-as-errors guidance
- the runtime and sibling-package support matrix
- the current matched-release policy between `mailglass` and
`mailglass_admin`
This admin-local page is intentionally a pointer page only. The admin package's
separate surface inventory still lives in
[`docs/api_stability.md`](api_stability.md).