Merge pull request #128241 from andreilean/patch-1

Add instance ID limitation info to durable-task-scheduler.md

Author: v-regandowner

articles/azure-functions/durable/durable-task-scheduler/durable-task-scheduler.md

@@ -152,6 +152,14 @@ Stale orchestration data should be purged periodically to ensure efficient stora
     | Orchestration custom status | 1 MB |
     | Entity state | 1 MB |
 
+- **Orchestration instance ID length:**
+  
+  Orchestration instance IDs are limited to a maximum length of 100 characters.
+
+  * Allowed characters: Printable ASCII only (letters, numbers, symbols like -, _, ., etc. Characters 0x20 through 0x7E)
+  * Minimum length: 1 character (cannot be empty)
+  * Instance IDs starting with @ are reserved for entities
+
 - **Feature parity:** 
 
     [Extended sessions](../durable-functions-azure-storage-provider.md#extended-sessions) are not available in the Durable Task Scheduler backend yet.
@@ -168,4 +176,4 @@ Stale orchestration data should be purged periodically to ensure efficient stora
 ## Next steps
 
 > [!div class="nextstepaction"]
-> [Choose your orchestration framework](./choose-orchestration-framework.md)
+> [Choose your orchestration framework](./choose-orchestration-framework.md)