I'm wondering how bricks are uniquely identified.
In the back of instruction booklets, the set parts are listed and the numbers match the numbers on the LEGO.com website. Each number seems to identify a part in a specific color. The design number listed on the website seems to identify the brick separate from color.
I guess my question is, are these numbers available for all bricks or did this only start later?
This same question goes for the identification of brick colors.
If there are any other ideas on how parts can or should be numbered/identified I would really like to know.