​This research deals with a difficult issue, which is the investigating the manuscript that has a single copy, and the problems surrounding this investigation, Therefore, We will discuss on three matters, the first of which is the awareness of the investigator and his knowledge, and the second: the confusion of the author's name and the attribution of the book to him, and the third: the certainty in writing the text and the attribution of sayings to their authors
and their sources. We concluded that the investigator of the manuscript that has a single copy should be flexible and patient, and that he has to carefully concern about the editing of the texts,
especially the texts that are related to the Shari'a, and that he has to correct the scientific errors in the footnote, if they contained in the text.