In his biography of George of Antioch (above, p.81), al-Maqrīzī employs the kunya or nickname Abū Tillīs for one of the protagonists. The meaning of this name rests upon two interdependent considerations: whether it belongs to cAbd al-Raḥmān or to Roger; and the precise meaning of tillīs.

The Arabic reads kataba ilā l-sulṭāni cAbdi l-Raḥmāni wazīri l-maliki Rūjāra bni Rūjāra maliki l-faranji l-ma crūfi bi-Abī Tillīsin ṣāḥibi jazīrati Ṣiqillīyata (‘he wrote to the sultan cAbd al-Raḥmān, the vizier of King Roger, son of Roger, king of the Franks, known as Abū Tillīs, lord of the island of Sicily’).

The word-order of the Arabic, which is reproduced exactly in the English translation, is not decisive, but strongly suggests that Abū Tillīs is employed of Roger. Only if it were possible to show that the phrase sāḥib jazīra Ṣiqillīya, ‘lord of the island of Sicily’, belonged to cAbd al-Raḥmān, rather than to Roger, could a strong syntactical case be made that Abū Tillīs also belonged to him. Indeed, Adalgisa De Simone assumes that both the kunya Abū Tillīs and the title ṣāḥib jazīrati Ṣiqillīya belonged to cAbd al-Raḥmān.