We appear to be debating in a slightly different context. CAA rules have clear definitions, but we as BA passengers are asked in this thread to abide by the letter of the BA rules, which are different (and more restrictive). If we break either the law or the rules, we may be punished. The CAA document says that law restricts only those devices that "can adversely affect the performance of [an airplane]" so if a Kindle cannot do this, it may be used.

I am referring to those posters who say the BA rule (all electronic devices must be switched off) has to be followed at all times, as it is a rule. I believe it's not really feasible for passengers to follow this blindly, and a reasonable approach to the BA rule should be (and is) taken for devices that do not affect the safety of aircraft.

Whether Kindles join this list of watches, pacemakers and hearing aids is the debate in my view.