Thanks christep & ExMo. I took a look at the fare rules for OWE, as published by BA, and it states that "not more than 2 segments may be between the UK and Algeria, Armenia, Azerbaijan, Bulgaria, Cyprus, Georgia, Greece, Israel, Macedonia, Malta, Morocco, Funchal, Portugal, Romania, Russia, Tunisia, Ukraine, Yugoslavia and the Middle East". So am I correct in understanding that IST is considered to be part of Europe, rather than the middle east?

And is there an exception to DXB if it is used as a point of transit?