A while back MGM·Lion (in his previous existence as MtheGM) said
> The three stanzas are set respectively in the Tyneside, Notts/Derby, and S Wales coalfields, where the boy is told respectively to prepare himself , in local dialect nomenclature, for life as a 'pitman', a 'collier', and a 'miner'.

I have assumed the middle one to be Scotland. But whichever it is, McColl's choice of the respective terms (as well as Dai going specifically for the anthracite) are icing on the cake of his songwriting BUT not always respected by later singers.