Merge branch 'master' into patch-42

Author: trent-green

exchange/exchange-ps/exchange/policy-and-compliance/Set-ProtectionAlert.md

@@ -18,6 +18,9 @@ Use the Set-ProtectionAlert cmdlet to modify alert policies in the Security & Co
 
 For information about the parameter sets in the Syntax section below, see Exchange cmdlet syntax (https://technet.microsoft.com/library/bb123552.aspx).
 
+> [!NOTE]
+> You cannot use this cmdlet to edit default alert policies. You can only modify alerts you have created using New-ProtectionAlert cmdlet.
+
 ## SYNTAX
 
 ```

sharepoint/sharepoint-ps/sharepoint-online/Add-SPOSiteDesign.md

@@ -111,7 +111,7 @@ Accept wildcard characters: False
 ```
 
 ### -PreviewImageUrl
-The URL of a preview image. If none is specified, SharePoint uses a generic image.
+The URL of a preview image. If none is specified, SharePoint uses a generic image. Recommended size is 400 x 421 pixels.
 
 ```yaml
 Type: String

sharepoint/sharepoint-ps/sharepoint-server/Import-SPWeb.md

@@ -269,11 +269,11 @@ Accept wildcard characters: False
 
 ### -UpdateVersions
 Indicates how to resolve situations where a file to be imported to a site already exists in that site.
-If the UpdateVersions parameter is absent, the import operation by default uses a value of 1.
+If the UpdateVersions parameter is absent, the import operation by default uses a value of 1 (Append).
 
 The type must be any one of the following:
 
--Add new versions to the current file
+-Append, which adds new versions to the current file
 
 -Overwrite the file and all of its versions (delete then insert)