Tags are a new feature of EndNote 21 and provide a visual organisational method.
First, create the tags you wish to use. These will be visible in the left pane and when clicked, will display all references with that tag.
- Click on the plus sign in the left pane next to Tags

- Give your tag a name and select a colour

Adding the tags to references
- Double-click on the reference
- In the summary tab, Manage Tags will be at the bottom of the top screen. Click this.
- Click on the tags you want for this reference

- Click Ok.
Alternatively, drag and drop your references into the tag folders in the left-hand pane.