The Russian Arabist V.I.Beliayev (1902—1976) was the first to mention the manuscript of an unknown biographical dictionary in the manuscript collection of the St. Petersburg Branch of the Institute of Oriental Studies. While working on the collection in 1953, he singled out this manuscript, acquired in 1939 from the Astrakhan book collector S.A.Alimov, as of “outstanding interest”. The scholar also determined its provenance as Khorezm and suggested that it is an autograph copy dating to the twelfth century. The manuscript was later examined by A.I.Mikhaylova (in drawing up a catalogue of Arabic manuscripts in the collection) and B.Z.Khalidov, who drew from it a biography of the famous scholar al-Zamakhshari. But it is only two decades after V.I.Beliaev’s first comments on the manuscript that his pupil, A.B.Khalidov, published a more detailed discussion of it in his two articles, Apart from an analysis of the manuscript’s contents and sources used, the author made the description of the manuscript. But what is more important, A.B.Khalidov was successful in attributing the work. However, at present, the results of his research need some corrections and additions inevitable after many years had elapsed from the appearance of his articles. The present article presents my own observations on the manuscript, which are basing certainly on the main results of Prof. Khalidov’s work.