There being so many people in Wales with the same name, it is customary to identify a man by his first name and his profession. For example, Dai the Post or Barry the Bread. Particularly apposite is the undertaker: Dai the Death.
Two stories illustrate this phenomenon very well. The first concerns a Russian spy trying to make contact with his Welsh mole in a small village in the valleys. He goes to the pub, and says to the landlord "The waters of the Don flow swift and strong", to which the landlord replies, "Oh, it'll be Dai the Spy you're wanting. First house on the left after the post office."
The other is a lament from another Dai: "All my life, I have been a carpenter specialising in building boats. Beautiful boats. Hundreds of them I've built. Hundreds. Perfect boats. But do the call me "Dai the Boatbuilder"? No, they bloody don't! And I only ever shagged one sheep."