The external granular layer of the cerebral cortex is commonly known as layer II. It should not be confused with the internal granular layer of the cerebral cortex (commonly known as layer IV).

Layer II is often lumped together with layer III and their union is referred to as layer II/III or layer 2/3.

Layers I, II, and III are together referred to as the supragranular layers, because they are above layer IV.