Comb Fault - Thumbprint

[Ms Biddy]

I've had a hard time finding example photos of the comb fault called a thumbprint. For all the show peeps out there, what exactly is a thumbprint comb? Are these examples of it?

 

[pipdzipdnreadytogo]

Based on the drawing of it in my standard, the first picture certainly appears to be what they call a thumb mark... But I also don't have much personal experience with such comb defects.

@Amer Can you confirm?