Focus X: A cumulative ability triggered by the initial dice roll that means, "When you roll at least one natural five with this unit's attack dice before re-roll, this unit gets +X power for its next attack." Only the first natural "5" counts. A five rolled after re-roll doesn't matter. Focus applies only to dice rolled for an attack, not to dice rolls for abilities like Retaliate. Accuracy can't increase the die roll to a natural "5."
Foresight
Foresight: [Effect]: A static, layered effect that means, "Whenever this unit attacks, you may predict the number of hits that will be rolled for that attack. If you're correct, gain the [effect]." For example, a unit with "Foresight: Gain 2 Force" will give you 2 force if you guess the number of hits rolled correctly.
Forewarning
Forewarning: [Effect]: A static, layered effect that means, "Whenever this unit is attacked, you may predict the number of hits that will be rolled for that attack. If you're correct, gain the [effect]. For example, a unit with "Forewarning: Gain 2 Force" will give you 2 Force if you guess the number of hits rolled correctly.
Fortitude
Fortitude: An isolated, static ability that means, "This unit can prevent unpreventable damage to itself." Units with Fortitude can prevent damage from units with Ferocity and "damage... that can't be prevented" by using Deflect, Evade, Parry, and other damage prevention abilities. Fortitude only allows a unit to prevent unpreventable damage to itself, not to other units. Putting damage counters directly on a unit is not the same thing as doing damage, and also can't be stopped by Fortitude.
INSERT
INSERT: A layered, static ability that means, "When this card is in play or stacked under the unit, the unit gets the following effect:" Insert works while in the build zone. The effect works while anywhere in the unit's stack. The granted ability remains to be the ability of its type. (For example, activated abilities granted by Insert may be disrupted.) The granted effect may not work in the build zone as per the rule for the rule for that effect.
Persuade
Persuade X: An activated ability that means, "Prevent up to X damage to this unit, and the attacking unit, if any, loses power for its next attack equal to the amount of damage prevented this way."