You can only add tags that are created by the user whose credentials you provided to authenticate with the server.
To retrieve the tags assigned to a profile from the Profiles tag collection,
1. Get the service document for the person's profile. See Retrieving the Profiles service document
2. Retrieve the value for the href attribute of the link element with the endpoint /profiles/atom/profileTags.do. The value of the rel attribute is http://www.ibm.com/xmlns/prod/sn/tag-cloud
3. Execute a PUT request on the value of the href attribute obtained in the previous step.
Note: When you update profile tags, the existing tag information is replaced with the new data. To avoid deleting all existing tags, retrieve the tags that you want to retain first, and send them back with this request
For the input, provide a profile tags Atom categories document.