Deeper front / shallower rear = more aerodynamic benefit (than vice versa).
Shallower front / deeper rear = less of a negative effect on handling from crosswinds (than vice versa).
In general, if you were actually racing/TTing and wanted maximum benefit, you'd have as deep as possible on the rear, and as deep as you can get away with in the conditions on the front. If you can only afford one seriously deep / plastic / spok wheel, you get more aero benefit from it being the front wheel.
If you're asking what HHSB correct form is, I don't have a clue.
Deeper front / shallower rear = more aerodynamic benefit (than vice versa).
Shallower front / deeper rear = less of a negative effect on handling from crosswinds (than vice versa).
In general, if you were actually racing/TTing and wanted maximum benefit, you'd have as deep as possible on the rear, and as deep as you can get away with in the conditions on the front. If you can only afford one seriously deep / plastic / spok wheel, you get more aero benefit from it being the front wheel.
If you're asking what HHSB correct form is, I don't have a clue.