The truth is there is no need to make sure an input is under 40 mA, even though I think it can avoid problems,
Yes that is right, there is a trend for putting series resistors in line with input pins in case of accidental setting to an output and then exceeding the input current of the output.
Personally I don't do that and have never had anything go wrong yet and I have been doing this a far few years.
Thanks for clearing this up. 