A more thorough explanation:

Definition: Sentence cap is a pretrial agreement in a military court where the maximum punishment that can be given to the defendant is limited.

Example: In a court-martial proceeding, a soldier may agree to a sentence cap of no more than six months in confinement in exchange for pleading guilty to a lesser charge.

Explanation: This means that even if the defendant is found guilty of a more serious offense, the maximum punishment they can receive is six months in confinement. The sentence cap is agreed upon before the trial begins and is a way for the defendant to limit their potential punishment.