You can only retrieve the profile entry for the user whose credentials you use to authenticate the request. In other words, you can only retrieve your own profile entry document or someone else's if that person provides you with his authentication credentials.
To find the endpoint to retrieve a users profile entry document follow the steps below:
1. Get the service document for the person's profile. See Retrieving the Profiles service document
2. Obtain the value of the href attribute within the collection element. The link will contain "/atom/profile.do". Perform a GET request with this link.
3. Inside the feed from step 2, find the "profileEntry.do" link where the rel attribute has the value "edit". Perform a GET request with this link.
Here is an example of the link: https://example.org/profiles/atom/profileEntry.do?key=7f0e8770-7251-4600-958e-7a530cfc1576
You can use this operation to obtain profile entry information that you want to preserve prior to performing an update. See Updating profile entries for more information. This method returns the Atom entry of a single profile as opposed to a feed of a profile or set of profiles.
The URI is the value of the href attribute of the element of the user's profile entry
Tip: If you want to edit the value of fields in a person's profile, get the rel="edit" link for a specific person's profile. To do so, retrieve a feed of the profile and specify the output=vcard parameter on the request.