Type 1 00s are characterized by their large size (50+ meters), tough armor and destructive capacity. They usually appear at Gap sites in small numbers (1-2 manifestations).
Type 2 00s are characterized by their smallers scale (20-30 meters) and larger numbers. They appear in a variety of phenotypes.
Type 3 classification is currently only used for 00s appearing outside the boundaries of Earth (Mars space and the Colonies).