A general verdict upon a plea of not guilty is either “guilty” or “not guilty,” which imports a conviction or acquittal of the offense charged in the accusatory pleading. Upon a plea of a former conviction or acquittal of the offense charged, or upon a plea of once in jeopardy, the general verdict is either “for the people” or “for the defendant.” When the defendant is acquitted on the ground of a variance between the accusatory pleading and the proof, the verdict is “not guilty by reason of variance between charge and proof.”