"Maybe to avoid confusion he should have said "routes within the British Isles" although, IIRC this has also upset a poster in the past, despite this being a recognised geo-political reference to the islands of Great Britain and Ireland"
This always gets me. I have a mate who dislikes 'British Isles' as a term. However 'British' actually predates all the current geo-political entities we know. The population of the isles were called Pretani over 2000 years ago, (Noted on several Greek maps) this word morphed into Bretani sometime post-Roman Empire. The native Britons were displaced by the Angles, Gaels, Saxons, Danes from the 6th to 11th century. (As were the Picts) So in fact the only remaining 'British' regions of the Isles are Wales and Cornwall. What is now Strathclyde was the last remaining kingdom of the Britons up until the 10th century.
Incidently Scotland is called that after the Scotti displaced the native Britons and Picts. The Scotti were the Gaelic Irish from the Kingdom of Dalriada (NE Irish coast)