update

Author: mumian

articles/azure-resource-manager/bicep/deploy-preflight.md

@@ -16,7 +16,7 @@ To understand preflight, it helps to see where it fits compared to other checks:
 3. [**What-If**](./deploy-what-if.md): Predicts exactly which resources are created, modified, or deleted.
 4. [**Deployment**](./deploy-cli.md): The actual execution where Azure builds the resources.
 
-When you trigger a preflight check, Azure doesn't just look at the code. It looks at the live environment and the resource provider (the service responsible for the specific resource, like Microsoft.Compute). It verifies:
+When you trigger a preflight check, Azure Resource Manager doesn't just look at the code. It looks at the live environment and the resource provider (the service responsible for the specific resource, like Microsoft.Compute). It verifies:
 
 - Parameter values (types, allowed values, missing required parameters)
 - Resource name conflicts (for example, globally unique names already taken)
@@ -28,12 +28,14 @@ If any of these checks fail, the deployment never starts.
 
 ## Limitations
 
+Preflight has these limitations:
+
 - Runtime errors: Preflight can't catch everything. For example, if a custom script extension fails during execution because of a typo inside a bash script, preflight won't see that error.
 - Dependent values: If Resource B depends on a property generated by Resource A (like a dynamic IP address), preflight might only perform a partial check because that value doesn't exist yet.
 
 ## Run preflight
 
-Preflight validation runs automatically when you use deployment validate or what-if style commands. For example, preflight validation runs during these operations:
+Preflight validation runs automatically when you use deployment validate or what-if style commands. For example, these operations run preflight validation:
 
 - ARM JSON or Bicep validation in Azure CLI or PowerShell
 
@@ -55,15 +57,16 @@ Preflight validation runs automatically when you use deployment validate or what
 
     For more information, see [Deploy Bicep files with the Azure CLI](./deploy-cli.md) and [Deploy Bicep files with the Azure PowerShell](./deploy-powershell.md).
 
-- what-if
+- What-if
+
     What-if includes preflight checks before calculating changes unless you configure it to skip the preflight. For more information, see [Running the what-if operation](./deploy-what-if.md#running-the-what-if-operation).
 
-- Azure portal "Review + create" step
+- Azure portal **Review + create** step
 
     Currently, the Azure portal only supports deploying ARM JSON templates. For more information, see [Deploy ARM templates with the Azure portal](../templates/deploy-portal.md).
 
-Preflight errors appear in the Activity Log but not in deployment history, because the deployment never began.
+Preflight errors appear in the activity log but not in deployment history, because the deployment never began.
 
 ## Next steps
 
-- To use the what-if operation, see [Bicep What-If: Preview Changes Before Deployment](./deploy-what-if.md)
+- To use the what-if operation, see [Bicep What-If: Preview Changes Before Deployment](./deploy-what-if.md).