At present, all rats are shown in six Varieties:
STANDARD – With short, smooth, glossy hair.
REX – With curly hair and curly whiskers.
TAILLESS – Complete absence of a tail, similiar to the Manx cats.
HAIRLESS – Complete absence of hair.
SATIN – Thinner, longer coat, with a lustrous sheen.
DUMBO – Larger ears set on the side of the head.

Each of these six varieties is grouped into six Sections by color and body markings. There are 33 distinct colors recognized among these Sections.
SELF - Entire body consists of the same uniform color. They are: Beige, Black, Blue, Blue-Beige, Champagne, Chocolate, Cocoa, Lilac, Mink, Platinum, Russian Blue, Russian Dove, Sky Blue, Black-eyed White, Pink-eyed White.

AOC (Any Other Color) - The entire body is of the same color, but the coat consists of individual hairs banded with two or more colors and evenly interspersed with colored guard hairs. In this Section the colors are: Agouti, Amber, Blue Agouti, Chinchilla, Cinnamon, Cinnamon Pearl, Fawn, Lynx, Pearl, Russian Blue Agouti.

AOCP (Any Other Color Pattern) - To have a combination of two or more colors other than white arranged in a recognized pattern. In this Section the colors are: Blue Point Siamese, Burmese, Himalayan, Russian Blue Point Siamese, Seal Point Siamese, Merle.

SILVERED - The coat is evenly interspersed with white hairs. In this Section the colors are: Silver Black, Silver Blue, Silver Chocolate, Silver Fawn, Silver Lilac, Silver Mink.

MARKED - There are ten groups within this Section, named according to the pattern of their markings, in any recognized color:

• English Irish have a white equilateral triangle on the chest.
• Irish have a moderately sized, evenly shaped white marking on the belly, four white feet, white tail tip.
• Berkshire have a completely white belly similar to the Fox mice; white feet, tail and small spot between the ears.
• Essex have markings similar to Berkshire, fading of color.
• Variegated have colored head and shoulders, white blaze on forehead, small and numerous color splashes from shoulders to tail, including the sides and tail and a white belly.
• Blaze have a white wedge shaped blaze on the face from muzzle to ears. Shown only in Berkshire or Variegated.
• Dalmatian have numerous color splashes distributed over the entire body with no solid clear-cut markings on a white body.
• Hooded have a white body with a colored hood to cover head, neck, chest, and shoulders, and a spine marking extending from hood to tail in an unbroken, moderately wide stripe without ragged edges or brindling.
• Bareback have a colored hood to cover head, neck, chest, and shoulders on a white body.
• Capped have a white body with a colored cap on head not to extend to throat or past the ears.
• Masked have a white body and a colored "mask" covering just across the face and around the eyes.

UNSTANDARDIZED - Any coat type, color, or markings not described, or any other unique physical feature.

At present, mice are shown in seven Varieties, according to their coat type, namely:
STANDARD - Short, sleek coat.
SATIN - Short, sleek coat, with a lustrous sheen.
LONG HAIR - Long, fine, thick, silky hair.
LONG HAIR SATIN - Long, fine, thick, silky hair with a Satin sheen.
FRIZZIE - Very dense, tightly waved or frizzed hair over entire body. Curly whiskers.
FRIZZIE SATIN - Tightly waved or frizzed hair with a Satin sheen. Curly whiskers.
HAIRLESS - Pink, thin, bright, translucent skin, free of scars or pimples. No hair.

Within each Variety, mice are grouped into five Sections by color and body markings.
SELF - Entire body consists of the same uniform color. They are: Beige, Black, Blue, Champagne, Chocolate, Coffee, Cream, Dove, Fawn, Gold, Ivory, Lilac, Orange, Red, Silver, White.

TAN and FOX - Both have the top color in any recognized color, with a contrasting underside: a rich golden-red tan in the TAN, a near white in the FOX. There is a clear and distinct line between the top and bottom color, running in a straight line along sides, chest and jaws.

MARKED - There are seven groups within this Section, named according to the pattern of their markings, in any of the recognized colors:

• Banded have a white band circling their body at their middle
  
• Broken Marked have as many colored spots or patches as possible, irregularly placed on a white background
  
• Broken Merle are Merle mice with white patches added
  
• Dutch have markings like the Dutch rabbit
  
• Even Marked have a uniform pattern, with clear cut and balanced spots or patches on a white background
  
• Hereford has a white face
  
• Rump White has a white rump marking
  
• Spotted Tans can be any of the Marked group, but those spots running into the belly area to be a rich, golden-red tan.
  
• Variegated have small and numerous color splashes on a white background, distributed over the entire body, free from any solid, clear-cut markings.

AOCP (Any Other Color Pattern) - To have a combination of two or more colors other than white arranged in a recognized pattern. The colors in this Section are: Blue Point Himalayan, Blue Point Siamese, Brindle, Himalayan, Merle, Reverse Siamese, Roan, Seal Point Siamese, Siamese Sable, Splashed.

UNSTANDARDIZED - Any coat type, color, or markings not described, or any other unique physical feature.

GENERAL DESCRIPTION - Mice should have a long, slim, racy body, large bold eyes, long clean head showing breadth and length, large expressive ears, long tapering tail, and an average length from nose to tail tip of 8–9 inches.