Summary
The American Heritage Dictonary defines type as: "An example or a model having the ideal features of a group or class; an embodiment." Therefore, type, when applied to rats, is an idealy structured animal to use as a guide. Or you could say that type is how a rat should be structured.

All breeders should strive to meet 'Type' inorder to improve their rats overall structure and, in the end, health.

In General
Rats should have a long racy body maintained in good weight, large bold eyes, long clean head showing breadth and length, large ears, long tapering tail, and an average body length of 8-10 inches.

All rats should be easy to handle, show no agression, rand should be free of physical or genetic defects.

Condition
This is basically summing up weight, coat health, and overall health of the animal. Rats should feel heavier than they look at first glance due to bone mass NOT from being overweight. Their coats should fit their coat variety standard with males having slightly longer and courser hair. A rat should never wheeze, sneeze, have scabs, or have discharge of any sort.

The Head
The head should be long and clean in outline. But not to pointed or narrow at the muzzle. The skull should be fairly wide, with the widest point between the eyes. The cheeks should smoothly transition to the muzzel with no pinching inwards. And the whiskers should fit the coat variety standard.
The Eyes
The eyes should be large, prominent, and round with constant animation and showing of interest.
The Ears
The ears should be set far apart on the head, standing erect (or horizonal in the case of Dumbo), and as free of creases and fold as possoble. They should be round in shape and should fit the size of the head.
The Tail
The tail should be heavy and round, thickest at the base and tapering to a fine tip, and only as long as the body. It should be free of kinks or scaring.