Merge pull request #2288 from MicrosoftDocs/chmoncay-patch-2

Update control-list-box.md

Author: tapanm-MSFT

powerapps-docs/maker/canvas-apps/controls/control-list-box.md

@@ -25,7 +25,7 @@ A **List Box** control always shows all available choices (unlike a **[Drop down
 
 **[Items](properties-core.md)** – The source of data that appears in a control such as a gallery, a list, or a chart.
 
-**Selected** – The data record that represents the selected item.
+**Selected** – The data record that represents the selected item.  You can only have one default selected item.  If you need multiple selected items please use the [Combo Box](control-combo-box.md) control.
 
 When you add a gallery, a list, or a chart, the property list shows **Items** by default so that you can easily specify the data that the new control should show. For example, you might set the **Items** property of a gallery to the **Account** table in Salesforce, a table named **Inventory** that you created in Excel and uploaded to the cloud, or a SharePoint list named **ConferenceSpeakers**.