I have added a task to someone that I met. Later I attach this person to a company. But the task is still connected to the person and the related to field is empty.
Example:
I create a task for Mr Jones. I don't know which company Mr Jones works for.
A week later I create company ACME and add Mr Jones to it.
When I view the task, it is still connected to Mr Jones, but the related field is empty although it should show company ACME.