There are mainly four Maltese standards

As (almost) each breeder says, he/she is breeding along the standard of Maltese or is trying to reach the standard, I may make some private notes to the differences here. I'm a member of the German Toy Association 'VK', which is connected to the German Kennel Club 'VDH', which is part of the worldwide 'FCI'.
FCI worldwide (80 countries) group 9 section 1 Nr. 065 standard
AKC United States of America Toy group standard
ANKC Commonwealth of Australia group 1 (Toys) standard
KC United Kingdom of GB and N. Ireland Toy standard
Beside these standards there're many more uncounted clubs e.g. UCI (United Kennel Club International) or Federación Canina Internacional (nothing to do with the above mentioned trustworthy FCI) and other organizations which breed maltese and also issue pedigrees. Though make very clear about which organization we're talking about.
size/weight < 25cm (10ins) Weight under 7 pounds, with from 4 to 6 pounds preferred. male 21-25cm, 3-4kg and female 20-23cm, 3-4kg
bite complete scissors bite (6/6) even, edge-to-edge bite or a scissors bite complete scissors bite (6/6)
pigmentation pads and nose black as KC but w/o naming pads as KC but with dark nails
coat Reasonable length, never impeding action, straight,
of silky texture, never woolly. Never crimped and without woolly undercoat.
curliness or woolly texture is objectionable. Color, pure white.
Light tan or lemon on the ears is permissible
Dense, shiny, glossy - falling heavily and of a silky texture
Pure white; a pale ivory tinge is permitted.
eyes Oval, not bulging, dark brown, black eye rims, with dark haloes very dark and round with black rims round and dark brown
head gently rounded viewed from front and sides
but never 'domed' or 'appleheaded'
skull is slightly rounded on top, the stop moderate 6/11 of the size, rather more broad, 90° Stop
*note: Australia and New Zealand are following the old KC standard but the bite is edge-to-edge or a scissors bite