Merge pull request #15088 from JoshGer/patch-10

RS service account restriction for invalid characters

Author: PRMerger20

docs/reporting-services/install-windows/configure-the-report-server-service-account-ssrs-configuration-manager.md

@@ -47,7 +47,7 @@ ms.date: 12/04/2019
 
 2. On the Service Account page, select the option that describes the type of account you want to use.  
 
-3. If you selected a Windows user account, specify the new account and password. The account can't be more than 20 characters.  
+3. If you selected a Windows user account, specify the new account and password. The account can't be more than 20 characters and can't contain special characters " / \ [ ] : ; | = , + * ? < > ' per Windows user account naming rules.  
 
      If the report server is deployed in a network that supports Kerberos authentication, you must register the report server Service Principal Name (SPN) with the domain user account you specified. For more information, see [Register a Service Principal Name &#40;SPN&#41; for a Report Server](../../reporting-services/report-server/register-a-service-principal-name-spn-for-a-report-server.md).