If you look at the chrome sources you can find this flag: const char kAutofillOffNoServerDataDescription[] = "Disables Autofill for fields with autocomplet

If you look at the chrome sources you can find this flag: const char kAutofillOffNoServerDataDescription[] = "Disables Autofill for fields with autocomplete off that have no " "crowd-sourced evidence that Autofill would be helpful."; So, at least in a company, this should work to avoid autocomplete making corporate apps unusable. another thing that seems to work for me, is adding role="combobox" along with autocomplete="off"