I’d like to follow on with a question. Hopefully one of our experts can assist.

Having spend much of the year bouncing between LON and GLA, where I have been able to put the ticket rules to good use, I was once thwarted when I tried to change from a GLA-LHR flight to an earlier GLA-LCY. If I recall correctly, my original flight was ticketed in R (Semi-flex domestic fare) and was told with this fare I was not permitted to switch from LHR to LCY. I have yet to find any documented guidance on this, so have remained slightly uncertain whether this is correct.