What's the final word on this? What are the appropriate suffixes to denote them correctly?
the word ‘Seth’ is not of Arabic origin. Yet the tradition of writing English names in arabic is to transpose consonants and vowels, in this case: s-ii-th
So my guess is the computer tries to Arabize it, treating the ii as a consonant (y) as in s-y-th
so add whatever vowel between the consonants. Suyith. Sayuth. Siyath. you name it :-D
But in Arabic it would actually just be pronounced: Seth