Add info on blocking unplanned identify event

Author: sarahrudy

src/protocols/enforce/schema-configuration.md

@@ -59,3 +59,7 @@ Setting this dropdown to Omit Traits will ensure that traits not defined in your
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 **IMPORTANT: Unplanned identify trait blocking is ONLY supported in cloud-mode Destinations. Events with invalid traits will not be blocked from sending to device-mode Destinations.**
+
+## Identify Calls - Common JSON Schema Violations
+To block _unplanned_ `identify` calls in your Schema Configuration, go to **Advanced Blocking Controls** and choose Block Events from the dropdown. Next, you will need to [edit the underlying JSON schema](https://segment.com/docs/protocols/tracking-plan/create/#edit-underlying-json-schema) and include a required trait you know won't exisit in your `identify` events. After you choose Block Event in the dropdown, any events that generate Common JSON schema violations will be blocked. 
+