If I remember correctly, if you received a ban for 24 hours of greater, after a year the ban will be "forgiven" per se and you will be able to apply for staff, given that you have no other punishments longer than 24 hours. I think this is what you mean by the forgiveness policy.
You can always file a dispute which can be found in my signature. Currently that is not a policy. Recently they changed the time banned from 7 days (1 week) on a first offense to Permanently
However, if you are asking if a ban will for pardoned after a certain amount of time, it will not be, and you can file a dispute at dispute.mcgamer.info , as Jokoy provided.
I hope this helps, though the information may be outdated as I am going off things from the past, and haven't asked. I will update this post if I am incorrect. Anyways,
QA; TL.