What is the ruling on supplicating, "My Lord, forgive me and my parents," after every prayer?

What is prescribed for a Muslim after prayer is to recite the remembrances (adhkar) established from the Prophet, peace and blessings be upon him, and then to supplicate with whatever good he wishes for this world and the Hereafter, such as supplicating for his parents. As for supplicating immediately after the salutation (taslim) and before the remembrances, this is contrary to the Sunnah.