For some locales, you can use the Lastname, Firstname format to display names in Cisco Jabber if the displayname directory field is empty or not available. This feature is only available for the following locales: Chinese (Hong Kong), Chinese (People's Republic of China), Chinese (Taiwan), Japanese, and Korean.
This display name format is configured by the SwapDisplayNameOrder parameter and is true by default, meaning that for the relevant system locales, when the displayname directory field is empty or not available, users' own display names and the display names of their contacts are displayed in the Lastname, Firstname format.