From Jeanne Craver comes this photo of the Davenport mare Adorned (Prince Hal x Moth by Tripoli), with the reference to the earlier discussion on pronounced white markings.
This is Royal Court Jester. He is not an Arabian horse (no panic yet). He carries less than 0.2 percent pinto blood from a single cross at the 10th generation. The remaining 99.8 is general list Arab blood. Tobiano is a dominant gene, so at least one parent need to carry it. I wonder, through, whether this is the same gene as that responsible for extra white markings? My question reflects my ignorance of equine genetics.