Would I be safe in assuming that this magical blue paint is fully covered as to its meaning in the current edition of the Highway Code ?
That's a good question - in fact there are road markings which have no mention in the Highway Code and no mention in law. Let me elaborate - on the big road near where I live, there was room for four lanes of traffic. No road markings at all. Cue traffic management scheme - road markings, raised tables, pinch points. I went to the exhibition - all along the middel of the road there is a metre wide white striped area, with dashed edges. Traffic engineer admits there is no force on law, just makes drivers think they cannot drive on it.
Sad to say that's what cycle lanes are for in traffi management schemes - they're not for the benefit of cyclists, they just cut down the perceived width of the road, in attempt to either reduce to one lane or to slow motors down. This explains the frankly useless nature of the underwidth farcilities we see, and if you put your traffic engineer head on and look at cycle lanes in this ligh you see why they're done.
Don't get me started on pinch points - as someone here said once, mobile speed humps using the soft, squishy bodies of cyclists.