I believe B.S. states the word competent and it says that a way of measuring competance is by use of 3rd party accreditiation schemes such as the BAFE SP203 scheme.
If the panel is of an open protocol variety then the competance issue comes into play.
Ark Angel, do you mean closed protocol?
Actually, it doesn't matter if a panel operates with an open or closed protocol (operating language). The protocol is provided by the device manufacturer who may or may not also manufacture control panels. The problems come with the configuration (programme) software of the control panel. If you don't understand how it works for any particular panel then you might not be considered competent to work on that control panel.
Competency is a matter of degree and surely if you make an error with something then you might be considered as incompetent, even with all the training and experience in the world!. (if you have had training and experience of something but make a minor error then you might get away with being competent but making an honest mistake).
Also competency obviously doesn't only apply to programmable control panels.
Finally, it is worth remembering that many programmable control panels are supllied by the manufacturer with a default BS compliant programme and if you don't need to reprogramme anything then you don't need to know how the programming works!