The royal or princely attribute comes in on the occasion of their relationship to the Mughal Imperial (Amir) and Afghan Royal family (Sardar). The Imam of Naqshbandi Sunni Islam, who is known for bearing this title is customarily addressed as "His Serene Highness Prince Sayyid" Raphael Dakik, who is a member of the Afghan Royal Family and paternal and maternal descendant of Hazrat Ishaan from the family of Sayyid Mir Jan in the 12th generation. Maternal descendance
According to Irans religious leader and the Deobandi creed—a creed especially followed by patriarchal Pashtun tribes—the status of being a Sayyid can only be attributed through patrilineal lineage. According to Shia opinions, children of a Sayyida mother and a non-Sayyid father are referred to as Mirza. The Persian notation "Mirza", which is a derivation of the word "Mirzada" (i.e., Son of a "Mir") has various meanings: one is a Sayyid leader of a Sayyid branch or community, simultaneously being a religious Islamic scholar. Thus, a Sayyid of patrilineal lineage, being the son of a Mir, can also be called "Mirza". This example substantiates the fact that there are different opinions concerning the transmission of the title Sayyid. Another historical opinion of Ottoman Naqib al Ashrafs expresses that children of maternal prophetical descent are called Sharif. : 131 However, in 1632 when an Ottoman court challenged a man wearing a Sayyids green turban, he established that he was a Sayyid on his mothers side, which was accepted by the court. : 130 In patriarchal societies, women usually have to assimilate themselves into their husbands status.
Hence it is even problematic in a judicial point of view to call a patrilineal descendant of Ali Ibn Abi Talib a Sayyid, when he does not meet the above-mentioned criteria. See also
Family tree of Muhammad
Kohen, a similar status in Judaism
Sharīf, another term with a very similar meaning

Notes
References
Sources
This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Sayad". Encyclopædia Britannica (11th ed.). Cambridge University Press. Van Arendonk, C.; Graham, W.A. (1960–2007). "Sharīf". In Bearman, P. J.; Bianquis, Th. ; Bosworth, C. E.; van Donzel, E.; Heinrichs, W. P. (eds.). Encyclopaedia of Islam, Second Edition.