Who are the 43 scribes of the revelation?

Biographers have differed on the number of the scribes of revelation (Kuttab al-Wahyi). Some have put their number at thirteen, while others have exceeded twenty. Ibn Kathir made them twenty-three, and among them were: the Four Rightly Guided Caliphs, Ubayy ibn Ka'b, Zayd ibn Thabit, Mu'adh ibn Jabal, Khalid ibn al-Walid, Al-Zubayr ibn al-Awwam, Mu'awiyah ibn Abi Sufyan, Al-Mughirah ibn Shu'bah, and others.