Sorry for not understanding but I do not speak English and I use the translator.
I want to know how Mibew version 1.6.4 stores the name of the visitors where the cookie.
If you can show me an email to give me advice please
Actually, I'm still not sure, what do you want. But I'll try to answer the question I think you've wanted to ask.
So, Mibew 1.6.4/1.6.5 stores a visitor's name in the cookie named WEBIM_Data. This name could be changed in libs/chat.php.