Hi Pwalenta,
When you pull the EndUser table using AXL SOAP request, if you get a bunch of other fields like site, building, nickname etc which are empty. Then the enduser is from local database. If there is data in those fields it could be imported via sync from a LDAP where that data existed.
Reference - https://communities.cisco.com/docs/DOC-40313
Thanks and Regards,
Geevarghese