Thanks for that Crank, seems to be a long way but I'll give it a shot.
How would you go around re-creating numerous blocks each time though?
We want flexibility in "simple" blocks created on layer "0" so they will accept colour, linetype parameters... of the hosting layer
Blockname PIT with visibilities Type1, Type2... Type5.
Type2 will be on many layers, Existing as well as Electrical layer, Communications layer...
In the table legend, blocks [visibility?] would have to be consistant colourwise...
Does my explaining make sense?