Index into Command ability in battle (kernel section 11) supplying this command’s fixed built-in effect (magic/effect id, attack type, power, hit count, element, status, animation), via computeCommandAction.
0xFF = no fixed effect: the action is chosen at runtime from the player’s selection (Attack, Magic, Draw, GF, Item all use 0xFF). Fixed-effect commands ( Card, Devour, Defend, Mad Rush, Treatment, Recover, Revive, Doom, Absorb, LV Up/Down) carry a real index. At setup, if the linked entry’s attack flags have the Revive bit, the command is flagged as a revive.