Step 1: Click on "My points".
Step 2: Click on the "Edit" button to see detailed information for that pinpoint.
Step 3: Here you can see the tags associated with that pinpoint. Perform the operations add, remove, search or select tags from list of tags.
Step 4: Select the pinpoints you want to add tags to.
Step 5: Click on "Actions" and then "Add tags".
Step 6: Write the tag and click "Add".