89c0777d_HiveMQ_1_4_1___User_Guide_Table_3__Static_properties_Description
[Property Name] ssl.applicationClientAuthentication [Default Value] false [Description] 
Enables or disables SSL client certificate authentication on the application layer. This does NOT affect transport client authentication. Essentially this enables HiveMQ plugins to provide permissions for users with specific client certificates.
HiveMQ 1.4.1 - User Guide
Description