[otrs] What versions of Firefox are supported?

Hi. What a beautiful ticketing system OTRS is. Small issue: I can't find a list of supported Web browsers. I've got a user on Firefox and they are getting the warning "The browser you are using is too old." 1. What versions of Firefox do you support, please? (I need to notify my user's IT department, as they are the ones who provide the Web browser.) 2. Could you please add to your documentation a list of supported Web browsers? Thanks again for a gorgeous product! Yours, Aleksey