This paper presents an outline for the meaning of library or reading registers as autobiographical historical index. Long before Safi al-Din al-Hilli’s systematic listing of his reading catalog, traditional transmission and reporting as ways of verification held a presence as manifestations of autobiographical deference and allegiance. In pre-modern and modern times, this proclamation recognizes the influence of forbears in matters of reading, company, and authorized audition. Among the religious and secularists, quotation, adaptation, appropriation, and direct mention suggest a cultural script where knowledge takes a written form or a library of some sort. Along with biographical constellations with their scattered autobiographic gleanings, snippets and references to libraries and books or authorities hold a special presence in cultural history. Especially among Sufis, antecedent or contemporaneous authority holds sway. On the other hand, eyewitness accounts, authorial testimonials are no less important as windows into intellectual growth and development. Thus, sayings, treatises, and practices shed light not only on the belated autobiographer, but also on a strong predecessor who usually functions in this script as the strong or unvanquished authority. Almost every autobiographical narrative works within a genealogy of knowledge, a library that significantly inspires modernists and generates a reading script or a complementary library register. Whether we speak of al-Qushayri, Abu Hamid al-Ghazali, Qurrat al-Ayn al-Hamadhani (in Shakwa al-gharib), ibn Maʿsum al-Madini, or ibn Ajiba, there is this exhaustive mention of readings that enforce an autobiographical pact, in Philippe Lejeune’s term, which is the staple of modern autobiography in the Arab world. Modernists’ works including Taha Husayn’s Al-Ayyam, Sayyid Qutb’s A Child from a Village, Hanna Mina’s Fragments, Jurji Zaydan’s Life, or Fadwa Tuqan’s Journey, convey and also transmit a library register that explains not only a boyhood and a future career, but also a wide cultural script that forms a central part in intellectual and social history. As each self-narrative, especially in the modern period, lays down his/her readings and contacts, we come across a wide autobiographical spectrum where readings and education become demarcating signs in an intellectual and cultural history. Salama Musa’s readings and intellectual affiliations for example are presented as the dynamic in the stride for modernity. He concludes by claiming his autobiography as meant to “to settle … [his] account with history,” a claim that others subscribe to in their intellectual maps.