Toy and Mini Aussie Breed Standard 
A blue merle Male Miniature Australian Shepherd - My Boy Tiger 
Breed Standard of the Miniature Australian Shepherd and Toy Australian Shepherd 
There are several different registries that accept the Toy and Mini Aussie. There are slight differences in the breed standard in each of those and often slightly different terminology used to describe coat color and other attributes. This is only a sample of a couple the standards you may find. 
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As Published by the Miniature Australian Shepherd Club of the USA
GENERAL APPEARANCE: The Miniature Australian Shepherd is a well-balanced herding dog of small to medium size. Bone is also moderate and in proportion to body size. He is attentive and animated, showing strength and stamina combined with unusual agility. Slightly longer than tall, he has a coat of moderate length and coarseness with coloring that offers variety and individuality in each specimen. An identifying characteristic is his natural or docked bobtail. In each sex, masculinity or femininity is well defined.
CHARACTER: The Miniature Australian Shepherd is intelligent, primarily a working dog of strong herding and guardian instincts. He is an exceptional companion. He is versatile and easily trained, performing his assigned tasks with great style and enthusiasm. He is reserved with strangers, but does not exhibit shyness. Although an aggressive, authoritative worker, viciousness towards people or animals is intolerable.
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As Published by America’s Pet Registry Inc.
The Miniature Australian Shepherd should be judged as if it were an Australian Shepherd in all respects other than size. Pay particular attention to disqualifications peculiar to the Miniature.
Preferred height for males and females at the withers is 18 inches and under; dogs with heights above 18 inches should be faulted to the degree of variance; quality, however, is not to be sacrificed in favor of size.
In proportion to height.
Straight to slightly wavy of medium texture and length, weather resistant, with undercoat varying in thickness with variation in climate; hair on head, ears, front of forelegs, and below the hocks is short and smooth; moderately feathered on back of forelegs and britches; moderate mane and frill, more pronounced in males than females. Serious fault: Non-typical coat.
Blue merle, red merle, solid black, red (liver), all with or without white and or tan (copper) markings: on all colors, areas surrounding ears and eyes dominated by color other than white; white is acceptable on neck (either in part or as a full collar) chest, legs, muzzle, under-parts, blaze on head and white extension from under-part up to four inches, measuring from a horizontal line at the elbow; white on head should not be predominate, eyes must be fully surrounded by color and pigment; hairline of white collar should not exceed the point of the withers. The blue merle and blacks have black pigmentation on nose, lips and eye rims; red merle and red do not; red merles and reds have liver (brown) pigmentation of the nose and lips; butterfly nose is not faulted under one year of age; small pink spots are permissible on merles’ noses, but should not exceed 25% of the nose on dogs over one year of age.
Disqualifications: Other than recognized colors; white body splashes, Dudley nose.
Head: Top skull flat to slightly rounded, length and width each equal to the length of the muzzle; moderate but well-defined stop.
Eyes: Clear, almond-shaped and of moderate size, set slightly obliquely, neither prominent nor sunken with dark, well-defined, perfectly positioned pupils; brown, blue, amber, or any variation or combination including flecks and marbling of eyes accepted; eyes must be expressive, showing attentiveness and intelligence.
Ears: Set high on side of the head, of moderate size, triangular with slightly rounded tip, and leather; at full attention, break forward and over from one-quarter (1/4) to one-half (1/2) above the base, or to the side as a rose ear. Serious faults: Prick ears and hound type ears.
Muzzle: Balanced and proportioned to rest of head; tapers slightly to rounded tip; see lip color under color, above.
Nose: Black and self colored according to coat; see nose color under Colors, above.
Teeth and Bite: Full complement of white teeth meeting as scissors or level bite: teeth broken or missing by accident are not penalized.
Disqualifications: Undershot; overshot greater than 1/8 inch.
Neck: Strong, firm, clean, and in proportion to the body; moderate length; slightly arched at the crest, setting well into the shoulders.
Top line: Appears level at a natural four-square stance.
Chest: Deep and strong, well-sprung ribs.
Body: Firm and muscular; strong and broad loin when viewed from the top; bottom line carried well back with a moderate tuck-up; moderately sloping croup, the ideal being thirty (30) degrees from the horizontal.
Forequarters: Shoulder blades are long, flat, fairly close set at the withers and well laid back; upper arms are relatively the same length as the shoulder blade, and attach at an approximate right angle to the shoulder line with forelegs droppings straight, perpendicular to the ground; straight and strong legs with strong oval, rather than round bone: medium length and very slightly sloped pastern; dewclaws should be removed, but are not penalized.
Hindquarters: Width of hindquarters approximately equal to width of forequarters at the shoulders; angulation of the pelvis and upper thigh (femur) corresponds to the angulation of the shoulder blade and upper arm forming an approximate right angle; clearly defined stifles, moderately bent hock joints; metatarsi (pasterns) are short, perpendicular to the ground, and parallel to each other when viewed from the rear; dewclaws must be removed.
Feet: All feet are oval shaped and compact, with well-arched toes and thick, resilient pads.
Tail: Straight, not to exceed 4 inches in length; natural bobtail or docked.
Movement: Smooth, free and easy; swift and very agile, with well-balanced, flowing gait with ground covering stride; fore and hind legs move straight and parallel with the center line of the body; as speed increases, the feet, both front and rear, converge toward the center line of gravity of the dog, while the top line remains firm and level.
Temperament: Attentive and animated; good-natured, but may be somewhat reserved in initial meetings; high-spirited, aggressive and authoritative worker, but not vicious toward people or animals; reserved with strangers but not shy.
It is important to note that in other countries the docking of tails is prohibited. Showing of dogs with tails is becoming more and more common and accepted here in the United States.
Viciousness or extreme shyness
Toy-like characteristics (domed head, bulging eyes, fine bone)
Undershot bite greater than 1/8 inch
Colors other than those recognized above in Colors
White body splashes, which means white on the body between withers and tail, on sides between elbows and back of hindquarters in all colors
Dudley nose
Wet flews (pendulous lateral part of the upper lip)
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