The sn surname is one of the standard LDAP attibutes attributes defined in RFC 2256 http://www.faqs.org/rfcs/rfc2256.html that UCLA Enterprisee Directory adpots. According to RFC 2256, sn, also known as X.500 surname, "contains the family name of a person." In the context of UCLA ED, this is the last name of the person represented by the identity entry in the UCLA Enterprise Directory.
The Enterprise Directory retrieves LAST_NAME_PERSON from the UID system via the Campus Data Warehouse (CDW) in realtime real-time manner. For each person, the UID system contains names recorded at 4 different university systems. They are Student Record System (SRS), Student Information System (SIS), Payroll Personnel System (PPS), and University Extension System (UNEX). Names from these systems are flagged in APP_ID field accordiingly accordingly as SR0, SI0, PP0, and UNX. The Enterprise Directory select the name to populate cn base on the following logic:
For students, contact data owner UCLA RegistrarorRegistrar's Office.
For employees, contact data owner UCLA Payroll Office.
For ASUCLA employees, contact data owner ASUCLA payroll office.