Vascoingles:
There is a list of the Spanish regions in the tachograph handbook.
A handy tip look at the letters that precede the road numbers in some region will definitley give a clue.
Some of them arePV Basque area
CL Castilla y Leon
Val Valencia
Cat Cataluna
CLM Castilla La Mancha
And Andalucia
Val Valencia
A Aragon
Ast Asturiasthat is far as it goes from memory but it obligatory to enter this every day
Mu bien amigo 