dsuser.applicationsubdata is used for the user's personal groups.
For example, to make a group call on a Push To Talk (PTT) mobile phone, create a PTT group with a list of friends. This list is part of dsuser.applicationsubdata in the database.
dsuser.applicationsysdata is used for company groups.
For example, the company decides to make you a member of the customer advocacy company group, which is part of your PTT mobile phone company group list. This list is part of the company dsuser.applicationsysdata in the database.
Both dsuser.applicationsysdata and dsuser.applicationsubdata are stored in Master Provisioning Data Store (MPDS) as binary format. This is done to save space in the database.