I think his point was Jinx on the opponent, Nullify on yourself.
You know, it seems counter-intuitive, but
both the Jinx on the caster and the Nullify on the target should be revealed when an Enchantment or Incantation is used by the caster on the target. My reasoning:
1) Both are revealed in the same (Counter Spell) step.
2) The trigger for mandatory reveal of Jinx is casting the spell, which happens as soon as the first step begins (so Nullify has not yet taken effect).
3) The trigger for mandatory reveal of Nullify is the creature being targeted by the spell, which happens prior to the Counter Spell step (so Jinx has not yet had a chance to go into effect).
You can choose to pay the mana cost for one or both, but neither will be around any longer once the one spell is cast since both are destroyed once resolved.
This, in essence, is just a restatement of what is in the other thread (mentioned by BoomFrog, above), but in a more general sense (as the target with Nullify can be any creature for this to happen).