Discretionary Role/Role Category used for?

I did find a different role category called - Discretionary role. Does anyone what it is used for. I don't see any documentation relating to the same. We have used Abstract, Job, Data, Duty roles, but this Discretionary role is something different I haven't seen and they are not appearing on some of the search.

Eg- Receipt Accounting - ORA_CMR_RECEIPT_ACCOUNTING_DISCRETIONARY

Role Category - SCM - Discretionary Roles

Any pointers highly appreciated.

Vj