Is it obligatory for pubic hair to be shaved completely (zero), or can it be trimmed lightly (to grade one) for both men and women?

Removing pubic hair is one of the acts of Fitra (natural disposition) that is unanimously recommended. It is best to remove all hair completely using Nura (a depilatory substance) or by shaving with a razor, as this is more conducive to cleanliness. Nothing of it should be left.