Think I know what your asking...but the way its worded would be a multi dimensional answer.
A Black Mouth Cur (BMC)...Yes. due to their being numerous variations of BMC. Red, Brindle, Ect....
A Yellow Black Mouth Cur (YBMC) I would say depends on the area with the ring necks. If its got spots .....throw it into the Catahoula or Leopard cur end....they usually will take anything with spots willingly.
Alot of East Texas Yeller Cur lines throw ringnecks. Or a touch of paint...ie White markings. Buy everyone has their own definition to the extent of each that is acceptable.
It also rolls over into what everyones definition of FULL BLOOD is.
We have gotten into that discussion before and seems to be no resolution.
