During the Minor Occultation (Ghaybat al-Sughrá), it is believed that al-Mahdi maintained contact with his followers via deputies (Arab. an-nuwāb al-arbaʻa or "the Four Leaders"). They represented him and acted as agents between him and his followers. Whenever the believers faced a problem, they would write their concerns and send them to his deputy. The deputy would ascertain his verdict, endorse it with his <answer>seal and signature</answer> and return it to the relevant parties. The deputies also collected zakat and khums on his behalf.
What would the deputy endorse the concerns with?
seal and signature