What specific coat feature is described as a hallmark for most onager types differentiating them?

Answer

White underparts and a clear, dark dorsal stripe

A key identifying feature of most onager types is the striking contrast provided by white underparts, such as the belly and muzzle, often paired with a clear, dark stripe running down the back.

What specific coat feature is described as a hallmark for most onager types differentiating them?
DonkeyOnager