docs: add breaking change note for BTP mergeType target validation

mehara-rothila · mehara-rothila · commit ed8af11b3582 · 2026-07-20T06:04:40.000+05:30
The new CEL rule rejects mergeType on Gateway/listener-targeting
BackendTrafficPolicies, which were previously accepted with the field
silently ignored. Document this as a breaking change.

Signed-off-by: mehara-rothila &lt;rothilamehara22@gmail.com&gt;
diff --git a/release-notes/current/breaking_changes/9195-backendtrafficpolicy-mergetype-rejected-on-parent-targets.md b/release-notes/current/breaking_changes/9195-backendtrafficpolicy-mergetype-rejected-on-parent-targets.md
@@ -0,0 +1 @@
+`BackendTrafficPolicy.spec.mergeType` is now rejected by CEL validation when the policy targets a parent resource (`Gateway`, including a specific listener via `sectionName`), matching the documented field contract and the equivalent SecurityPolicy validation. Previously such configurations were accepted but the `mergeType` field was silently ignored; stored objects keep working, but the next create or update must remove `mergeType` or target an xRoute.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+`BackendTrafficPolicy.spec.mergeType` is now rejected by CEL validation when the policy targets a parent resource (`Gateway`, including a specific listener via `sectionName`), matching the documented field contract and the equivalent SecurityPolicy validation. Previously such configurations were accepted but the `mergeType` field was silently ignored; stored objects keep working, but the next create or update must remove `mergeType` or target an xRoute.