Taleo how to restrict a candidate refering once he was already referred or applied ?

Summary

Taleo how to restrict a candidate refering once he was already referred or applied?

Content

Hello,

How can we restrict referring  a candidate by an agent/referral so that only ONE referral will be the owner of the candidate ,and another
referrer wont be able to refer the same candidate (also not for another requisition ).? we set up the ownership period for 182 days .- we would like to allow the option to refer again after 182 days .

what should be the values of the following properties ? : 

1) Ownership Configuration for Agent and Employee Referrals - Submission and Candidate Ownership?
2) Accept Referrals from Agents for Known Candidates or Submissions