Pour information la
FAQ du symbole untap est déjà parue.
***New Symbol: The Untap Symbol***
* The untap symbol is the analog of the tap symbol. Represented as {Q} in rules documents, it looks like a white J-shaped arrow (with the arrowhead pointing up) on a black circle.
* The untap symbol appears only in the costs of activated abilities. It means "Untap this permanent."
* If the permanent is already untapped, you can't play its
ability. That's because you can't pay the "Untap this permanent" cost.
* The "summoning sickness" rule applies to
. If a creature with an
ability hasn't been under your control since your most recent turn began, you can't play that ability. Ignore this rule if the creature also has haste.
* When you play an
ability, you untap the creature with that ability as a cost. The untap can't be responded to. (The actual ability can be responded to, of course.)
Je laisse la traduction complète à quelqu'un de plus compétant mais voici quelques points importants (dont certains dont nous nous doutions déjà):
On ne pourra pas utiliser la capacité d'un permanent requérant de payer

si le permanant en question est déjà dégagé (ça parait logique).
Comme pour le symbole

, la règle du mal d'invocation s'applique pour le symbole

(ça c'était quand même la grande interrogation sur ce nouveau symbole).