Singh
As per the instructions of Guru Gobind Singh, the use of Singh as a middle or a last name is mandatory for all baptized male Sikhs since 1699, regardless of their geographical or cultural binding. The surname has also been widely adopted by other groups of India like Yadavs and Jats. Some Brahmins like Bhumihar Brahmins and Maithil Brahmins also use this name. "Singh" has gradually emerged as a hereditary title to be used as a middle name, highlighting connections to a warrior status or occupation. However, this is not an exclusive usage, and many Hindu groups including Scheduled Castes and Vaishya have adopted this title without any significant warrior status or ties.