So far as I can tell, and I've talkked to traffic cops and IAM on this one, the current highway code does not illustrate these particular types of lane markings.
There is a mile long stretch of the A27 outside Brighton that has just one of these lanes on both the east and west cariageways but......
You enter the lane from a sliproad off a roundabout and have a straight run, no lane changing, onto the next off slip.
Traffic from the A27 can join this lane anywhere on its length apart from the last few yards.
A class 1 police driver, the one on this site may confirm, has told me that for the purposes of the law they would classify such a marked lane as a separate road (they cant use the highway code as reference for best practice as they can in most motoring cases due to the missing info in the HC).
But..... such road lanes should be used with caution. Unnecessary lane changing should be avoided and any rapid manoeviring could be classified as careless or dangerous driving.
Having said all this the particular lane in question is the scene of lots of minor shunts in the rush hour with people in the lane deliberately blocking cars from the main A27 onto the exit slip. Not the safest of places first thing in the morning but fine during normal traffic.
Take care out there.
Over to Class One perhaps