A book that searches in the science of hadith sciences, which is the knowledge of the modern, narrators, and nicknames. The letters of the Arabic language except "Abu Qasim put it at the beginning of the book, and he mentions the name of the narrator and the name of his Sheikh or the name of his student. And the book is the abbreviation of the book of Al -Asami and Al -Knani by Abu Ahmed Al -Hakim, may God have mercy on him