Microsoft Outlook doesn't have built-in support for tags. To provide tag support with MilkSync, tags from Remember The Milk will sync as categories in Microsoft Outlook.

To distinguish tags from lists (which also sync as categories), each tag name is pre-fixed with a "#" in Microsoft Outlook i.e., the tag errand from Remember The Milk will show as the category #errand in Microsoft Outlook.

To create a new tag within Microsoft Outlook, simply create a new category and start the name with a "#". When you sync with MilkSync, this category name will automatically become a tag in Remember The Milk.