The norm for transliteration of Arabic titles in our electronic catalogue system is the international standard ISO 233 (International Organization for Standardization's norm for Transliteration of Arabic characters into Latin characters) which is also the german DIN 31635. So one should whrite in the input field of the online catalogue 

t for thāʾ, g for jīm, h for khāʾ, d for dhāl, s for shīn, g for ghayn; a for tāʾ marbūṭa, iya for nisba feminine singular; ai and au for diphthongs, iy and uw for doubling of wāw and yāʾ.

To Arab personal names applies the standardised form of RAK-WB (e.g. Ibn-Bībī, Abu-'l-Faḍl, ʿAbdallāh, ʿAbd-ar-Raḥmān, Muʾaiyad fi 'd-Dīn).