Agree on the skyway code. Good starting point. But bit disappointed to see the correction on the website which says:
On page 87 (print) 88 (online), the guidance regarding the transition level does not reflect current policy that the lowest available Flight Level after setting 1013 hPa at the transition altitude is always at least 1,000 ft above the transition level.
It should read "transition ALTITUDE" at the end - not the only example of poor error checking in the broader CAA document set.