Very interesting

good luck dr Jamal

I don't think that franco-arabe means texting someone in Arabic. As hyphenation suggests, it is a mixture of Arabic and French, a case of code-mixing in the dialects of Morocco, Algeria, and Tunisia as a result of French cultural colonization. True, most often in texting people French is transliterated in Arabic, but that does not make such texting franco-arabe.

Thank you Zouheir Maalej.

Yes, it right. I found an MA progarmme called " French: Franco-Arabic Studies Track".

But I am wondering why Franco Arabic is also used for Arabic texting by everywhere in google.

I believe that is because Arabic texters mix Arabic and English alphabets and digits which might be similar to Franco-Arabic which you referred to above.