Why are you trolling. I knew it without checking, but I give you the wiki reference.
"During the Ayutthaya Kingdom period, the Iranian community in Thailand consisted primarily of merchants. They are recorded in some memoirs of their fellow merchants, the Dutch East India Company, as well as in the Safine-ye Solaymani ("Ship of Solayman"), an account of a Persian embassy to King Narai. Some descendants of Iranians from the Ayutthaya period converted to Buddhism, and continued to retain influence in Thai public life to the present day; one prominent example is the Bunnag family, whose ancestor "Shaykh Ahmad" is said to have come from Qom and arrived at Ayutthaya in 1602."
David Broadfoot And the Franks are the ancestors of the French. Your point makes sense because when the French embassy came to the king Narai, there was an influent Persian community in Ayuthaya. They probably told the Thai elite that those white people where Faranghi.
True for the majority, but not always. I was once at the Malaysian border Thai checkpoint. I asked the immigration officer in Thai for a TM entry card, she replied "Thai nationals don't need them anymore". Oh God I felt proud 😍.
Farang is the alteration of Farangset, Thai pronunciation for "Français" which means French in French language. The first Whites staying in the kingdom where people sent by king Louis 14th to king Narai. In Khmer it's Barang because they don't have the F sound. In Laos, Farang simply means France.
ie People who shared their experience on Facebook groups. I can't speak about the silent ones, that's why I can't say if the insurance was requested to all non-O or not.