Purpose: Classification and categorization of counterfeit manuscripts and the amount of alteration by scribes or forgers considerably helps us know about the position of each and its counterfeit version. In this respect, we should pay attentions to some essential points.
Method: An historical literature survey method was employed
Findings: The amount of alteration in a manuscript and the period it was committed was traced to. Many of the forgeries and alterations were committed on manuscripts of historical significance such as Qabus Nameh, Dasatir-e-Asemani and Khayyam Quatrains.
It is possible to classify the manuscripts which have been counterfeited even the ones which have undergone forgery to a lesser extent, by historically and traditionally surveying the existence of forgers in history. The writer hopes that this research about the counterfeit works helps us know more about the knowledge of proof reading.