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Fix capitalization.

Author: AnnaMHuff

articles/ai-services/agents/concepts/model-region-support.md

@@ -28,7 +28,7 @@ Azure AI Agent Service supports the same models as the chat completions API in A
 | westus        | ✅                         | ✅                          | ✅                            | -                   | ✅                          | -                           | ✅                               | - | -                          | ✅                         | ✅                          | -                              |
 
 
-## Non-microsoft models
+## Non-Microsoft models
 
 The Azure AI Agent Service also supports the following models from the Azure AI Foundry model catalog.