Kātyāyana (कात्याय ) also spelled as Katyayana (c. 2nd century BC) was a Sanskrit grammarian, mathematician and Vedic priest who lived in ancient India.Katyayana Smriti contains a total of 29 sections. These sections cover a range of topics related to the various religious rites and ceremonies, in a comprehensive manner. They also deal with the duties of a Brahmin, a man and a woman. Some sections are concerned with the rites pertaining to deceased persons, while others concentrate on the marriage ceremony. There is a detailed description of the proper method in which the fire for the ‘Yagna’ (a sacrificial ceremony) is to be kindled. Also stated are the various codes of conduct to be followed during the ceremony.