The W Locus has two different alleles in it: ‘W’, and ‘w’. ‘W’ is the most dominant and ‘w’ is the most recessive.

W: Non-Wideband
w: Wideband

NON-WIDEBAND
The ‘W’ allele is the non-Wideband alle. All varieties without the Wideband coloring must have at least one of these alleles. If they have two of these alleles, then they are homozygous (Meaning it is “pure” for that alleles, so that it cannot produce anything recessive to it no mater what it is bred to.) for non-Wideband.

The following varieties have the non-Wideband alleles:
All varieties except Tan and wideband-influenced versions of the variety.

Non-Wideband can carry Wideband.

WIDEBAND
The wideband allele extends the intermediate band and removes the undercolor on the belly. Examples are Otter with the wideband gene becomes Tan.

The ‘W’ gene is the Wideband allele. All wideband varieties must have two of these alleles, and are automatically homozygous for Wideband.

The following varieties have the Wideband gene allele:
Wideband Chestnut (example is Belgian Hare coloring), Tan, true Red.

Note: Wideband is linked to heavy rufus (making the orange parts a deeper red color), which is why many wideband colors have such intense red color. However, rabbits can be lower rufus and still be wideband! The easiest way to check is to blow into the coat to check the width of the intermediate band in agoutis and check the belly color. Wideband on self colors can be very difficult to impossible to tell apart from non-wideband.