8.171 classifying adjectives

When you put two classifying adjectives in front of a noun, you have to decide whether the adjectives relate to the same system of classification or to different systems.

For example, 'geographical' and 'geological' relate to the same system; 'British' and 'industrial' relate to different systems.

When you put two classifying adjectives in front of a noun, and the adjectives relate to the same classifying system, you put 'and' between them.

When the adjectives relate to different classifying systems, you do not put 'and' between them, or use a comma.