HRP5102 - Deregistered field, what sets it to true when an employee is terminated?

Hello experts,

When an employee is terminated, I understand the IS_INACTIVE field is set to true, thus identifies the candidate as external. However, in order for periodic_services to remove the central person ID and relationships, the DEREGISTERED flag must set to true.

What triggers this DEREGISTERED field to become set to true?

Kind regards,

Garrett Meredith