I don't see what you're getting at. I admit it's not exactly written in the clearest english (what official document is
) but all it's saying is don't go from (for example):
2600 - 7600 - 7610 (which is available as a discrete code somewhere probably). The three 'special' squawks will set the bells and whistles off everywhere. (well - a feeble and annoying electronic 'squeak' where I work
)
To be quite honest this is over-regulation in its purest sense. Use a bit of common sense when you change squawk, don't inadvertantly select an emergency code - it's not difficult. If you're worried about it then play safe and select standby whilst changing.