On each user profile, you can allocate Tags using the "Tags Assigned To User" section.
To create a new Tag, type your desired text into the text box name "Tag Text".
Now click "+ Add and attach new Tag".
To add an existing Tag to this user click the drop down list, select the relevant Tag and click "+ Add existing Tag".
You will now see all Tags allocated this user in a list.
All Tags created will be shown in the Customer Management, you can now allocate these to any number of users by selecting the user and clicking "Manage Tags".
You can see the existing Tags for these users at the top, and then add existing Tags or create new ones.