in user/lib.php, the function user_get_user_details() return phone1 and phone2 if a user has moodle/course:viewhiddenuserfields / moodle/user:viewhiddendetails capabilities. Address is also depending of them (but different coding way?). The other user fields do not depend of these capabilities.

We need to check if it's normal that phone1/phone2/address have specific behavior.