diff --git a/doc/api/protected_branches.md b/doc/api/protected_branches.md
index 0b308a6c68e98064cf91552279e5e61f04ed99b8..fc66a75860ab5d6e89a7f8d31ad76abfc555d9b6 100644
--- a/doc/api/protected_branches.md
+++ b/doc/api/protected_branches.md
@@ -318,6 +318,18 @@ Supported attributes:
 | `push_access_level`            | integer           | No       | Access levels allowed to push. Default is `40` (Maintainer role). |
 | `unprotect_access_level`       | integer           | No       | Access levels allowed to unprotect. Default is `40` (Maintainer role). |
 
+When you configure access levels:
+
+- You can set multiple access levels simultaneously for `allowed_to_push` and `allowed_to_merge`.
+- The highest access level determines who can perform the action.
+- If you set access level `0` (no one) and other access levels for the same branch, the most permissive access level applies.
+
+This behavior differs from the UI, which automatically clears other role selections
+when you select **No one**.
+
+For example, if you set both `access_level: 0` (No access) and `access_level: 40` (Maintainer role)
+for `allowed_to_push`, users with at least the Maintainer role can push to the branch.
+
 If successful, returns [`201 Created`](rest/troubleshooting.md#status-codes) and the
 following response attributes:
 
@@ -759,6 +771,9 @@ Supported attributes:
 | `allowed_to_unprotect`         | array             | No       | Array of unprotect access levels, with each described by a hash of the form `{user_id: integer}`, `{group_id: integer}`, `{access_level: integer}`, or `{id: integer, _destroy: true}` to destroy an existing access level. Access level `No access` is not available for this field. Premium and Ultimate only. |
 | `code_owner_approval_required` | boolean           | No       | If `true`, prevents pushes to this branch if it matches an item in the [`CODEOWNERS` file](../user/project/codeowners/_index.md). Premium and Ultimate only. |
 
+For information about how access levels interact when you set multiple values,
+see [Protect repository branches](#protect-repository-branches).
+
 If successful, returns [`200 OK`](rest/troubleshooting.md#status-codes) and the
 following response attributes:
 
diff --git a/doc/user/project/repository/branches/protected.md b/doc/user/project/repository/branches/protected.md
index f6bf4fab2908ee581cf17527a1e0942166b88677..644d6f4a5c57ce4a8f83cf7b9d56264e12a59018 100644
--- a/doc/user/project/repository/branches/protected.md
+++ b/doc/user/project/repository/branches/protected.md
@@ -131,6 +131,12 @@ Users with this permission can merge through merge requests even without
 
 {{< /alert >}}
 
+When you select **No one** for either **Allowed to merge** or **Allowed to push and merge**, the UI
+clears other role selections.
+This behavior differs from the API, where you can set multiple access levels simultaneously.
+For more information about API behavior, see the
+[Protected branches API](../../../../api/protected_branches.md).
+
 ### Protection strategies by branch types
 
 Different branch types require different protection levels based on their purpose and