Use

Use is a gameplay term.

Details
It is the act of paying the cost of a card, and then following the cards instructions.

It was first referenced on Cyber I Choice.

The following game actions count as using a card.
 * Summon — (Creature)
 * Cast — (Spell)
 * Generate — (Cross Gear)
 * Fortify — (Castle)
 * Expand — (Field)
 * Putting an Impulse into the battle zone.

The steps to play the game actions are as follows;
 * 1) Reveal the card you want to play.
 * 2) Choose any modes for the cards. (if applicable)
 * 3) If you have additional or alternate costs, declare what you paying.
 * 4) If there is a cost increase or decreases, apply them.
 * ) Declare any targets (Such as creature you are evolving on, spell target, or castle you are fortifying)
 * 6) Pay the total cost.

The cards are then resolved based on their card type.
 * A creature, cross gear, field or impulse is put into the battle zone.
 * A spell is put into your graveyard.
 * A fortress is attached to one of your shields.

Cross Gears already in the battle zone are not considered to be a "use". They may cross to one of your creatures without triggering the ability of Completely Unidentified.