diff --git a/windows/configuration/start-layout-xml-desktop.md b/windows/configuration/start-layout-xml-desktop.md
index eb2b250fba..835de0b215 100644
--- a/windows/configuration/start-layout-xml-desktop.md
+++ b/windows/configuration/start-layout-xml-desktop.md
@@ -54,7 +54,7 @@ The following table lists the supported elements and attributes for the LayoutMo
 | RequiredStartGroupsCollection</br></br>Parent:</br>LayoutModificationTemplate | n/a | Use to contain collection of RequiredStartGroups |
 | [RequiredStartGroups](#requiredstartgroups)</br></br>Parent:</br>RequiredStartGroupsCollection | Region | Use to contain the AppendGroup tags, which represent groups that can be appended to the default Start layout |
 | [AppendGroup](#appendgroup)</br></br>Parent:</br>RequiredStartGroups | Name | Use to specify the tiles that need to be appended to the default Start layout |
-| [start:Tile](#specify-start-tiles)</br></br>Parent:</br>AppendGroup | AppUserModelID</br>Size</br>Row</br>Column | Use to specify any of the following:</br>- A Universal Windows app</br>- A Windows 8 or Windows 8.1 app |
+| [start:Tile](#specify-start-tiles)</br></br>Parent:</br>AppendGroup | AppUserModelID</br>Size</br>Row</br>Column | Use to specify any of the following:</br>- A Universal Windows app</br>- A Windows 8 or Windows 8.1 app</br></br>Note that AppUserModelID is case-sensitive. |
 | start:DesktopApplicationTile</br></br>Parent:</br>AppendGroup | DesktopApplicationID</br>DesktopApplicationLinkPath</br>Size</br>Row</br>Column | Use to specify any of the following:</br>- A Windows desktop application with a known AppUserModelID</br>- An application in a known folder with a link in a legacy Start Menu folder</br>- A Windows desktop application link in a legacy Start Menu folder</br>- A Web link tile with an associated .url file that is in a legacy Start Menu folder |
 | start:SecondaryTile</br></br>Parent:</br>AppendGroup | AppUserModelID</br>TileID</br>Arguments</br>DisplayName</br>Square150x150LogoUri</br>ShowNameOnSquare150x150Logo</br>ShowNameOnWide310x150Logo</br>Wide310x150LogoUri</br>BackgroundColor</br>ForegroundText</br>IsSuggestedApp</br>Size</br>Row</br>Column | Use to pin a Web link through a Microsoft Edge secondary tile |
 | TopMFUApps</br></br>Parent:</br>LayoutModificationTemplate | n/a | Use to add up to 3 default apps to the frequently used apps section in the system area |