We had a debate whether or not it is a service foul if you are on your tip toes, but your heel is "on the line". Not touching the line but just hovering over the line when serving.
The lady with the arrow would be serving and she would be standing where the circles are, but her heels would be on the line in the air.

Foul or not? I really couldn't find this information anywhere. I'm guess it's not a foul since you are not touching the line.
The lady with the arrow would be serving and she would be standing where the circles are, but her heels would be on the line in the air.

Foul or not? I really couldn't find this information anywhere. I'm guess it's not a foul since you are not touching the line.