The early breeding stock with very little white were referred to as "Barris". The "Blazies" had the white blazes and chest markings we typically see in Bernese.
Symmetry of Markings is desired. Rust appears over each eye, on the cheeks reaching at least to the corner of the mouth. There is a white blaze and muzzle band.
Berner facial markings can deviate from the 'ideal' description in the Breed Standard.
Breeder and owner focus on markings has historically been a subject of discussion. Preferences for dogs with less white or more white on muzzle band and blaze seem to rest in the eye of the observer. Blue eye color often appears on dogs with more white, but 'perfectly' marked dogs also can have blue eye(s).