In the SCA, and possibly in other groups, you cannot have, as part of your "persona name," anything that is a title, unless you can show that title was also used as an "ordinary" name. Even then, you have to use it in such a way it cannot be mistaken for a title. The example usually trotted out is Regina the Laundress is OK (Regina having been shown used by "ordinary people"), but Regina of London is not OK.

In this article, I am going to talk about the "title," Fāris (I put "title" in quotes because in pre-17th century Islamdom it wasn't really a title; it is used as such in the SCA and possibly elsewhere as an equivalent of Knight). If it were to be used as a name per se, the first step is to show it being used as such by "ordinary people". The second, of course, is to use it in such a way it cannot be taken as a title. The second part, dear reader, is up to you. However, I can definitely deal with the first part. That is, I can show it being used as a name per se.

I'll start with someone I've dealt with at length elsewhere, Ibn Munqidh. In An Arab-Syrian Gentleman and Warrior...., Philip K. Hitti's translations of the memoirs of Usāmah ibn Munqidh, ibn Munqidh talks at some length about a person, a Kurd, whose name was Fāris. Specifially, he says:

Others fight because of loyalty. An illustration of this is the case of a Kurd named Fāris... who, true to his name, was a cavalier, and what a cavalier he was! {emphasis added}

There's another person I've dealt with at length elsewhere who is associated with my next example. Ibn Baṭṭūṭa, on his return to his home in (Tangiers) was commanded to dictate his memories of his long journey; the person who gave that command was Abū ʻInān Fāris, the ruler of much of the Maghrib and parts of Ifriqiya in the mid 14th century. Every source I've found treats Fāris as his ism. As well, he was succeeded by two of his sons, one known as Abū Zayyan Muḥammad ibn Fāris and the other as Abū Bakr ibn Fāris. While I have seen people with a nasab based on the father's title, they are always in forms like "ibn al-Sulṭān" or "ibn al-Shaykh" - - - "son of the (title)", not "son of (title)". Given the format of the father's and the sons' names, I cannot see how Fāris would not have been an ism - - - a personal name.

In The Encyclopaedia of Islam, 2nd edition, sn Marīnids, is an article on sultans of the Marīnid dynasty, who ruled various parts of North Africa's Mediterranean coast at various times. Among them was the Abū ʻInān Fāris mentioned above. As well, in that article, mention is made of his brother (I believe) Abū Fāris ʻAbd al-ʻAzīz, and a later sultan of the same name (late 14th century), and an Abū Fāris Mūsā (same time frame; son of Abū ʻInān).

In the same work, sn ʻAnnāzids, mention is made of Ḥusām al-Dīn Abu 'l-Shawk Fāris, who dates from the early 11th century.Given the formation of names in Arabic, I read this as having Fāris as the ism; that is, as the given name. Later, sn Fāris b. Muḥammad, the same person is given as Fāris b. Muḥammad, alias Ḥusām al-Dīn Abu 'l Shawḳ, reinforcing the idea that Fāris is his given name.

One of the dynasties that competed with the Marīnids for control of North Africa's Mediterranean coast were the Ḥafṣids. In the early 15th century the Ḥafṣid sultan was Abū Fāris ʻAbd al-ʻAzīz, who should not be confused with the two Abū Fāris ʻAbd al-ʻAzīz's of the Marīnid dynasty.

One last example: As stated in A History of the Maghrib in the Islamic Period by Jamil M. Abun-Nasr, on page 113 (https://books.google.com/books?id=jdlKbZ46YYkC&pg=PA113#v=onepage&q&f=false), the "vizier" of Abū ʻInān was named Fāris b. Maymūn. This, too, can reasonably be interpreted as having Fāris as the ism.

To sum up; Fāris can be documented as an ism, a given name, from the early 11th century to the early 15th. Thus, it is not only a "title", but an ism as well.