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I think it's a reference to the 110 degrees, which is commonly seen.
Johnny uses 110 degrees, so I will too..
Without knowing -why- the 110 degrees is used, it's not "design".
The vee-angle is predicated on the airplane use.
A rudder-elevator airplane might use 90 degrees, for the most effective rudder response.
An aileorn plane which doesn't use the rudder as the primary turning control can relax the vee to 110 degrees, giving the elevator more authority.