>> > I am trying to completely disable the zsh completion system.
>>
>> Does this do what you want?
>>
>> bindkey -r '^I'
>
> No, I have already unbinding Ctrl+I. It is also not helping.
The bindkey command I posted above makes TAB do nothing.
% ls<TAB>
Nothing happens.
If this isn't what you are looking for, please explain what you want to achieve.
Roman.