Use for roles codes ending in _OBI

Summary:

Does anyone understand what roles ending in _OBI drives? E.g. the employee role contains duties:

ORA_HRT_WORKFORCE_PROFILE_WORKER_DUTY

ORA_HRT_WORKFORCE_PROFILE_WORKER_DUTY_OBI

both have the description:

Performs workforce profile duties as an employee or contingent worker.

However when i remove the one ending in _OBI, the role appears to still function as expected in the workforce profile area.

Assume this is to do with OTBI, but unclear what?