The “Rape Shield” Rule - Mil. R. Evid. 412.
Rule 412. Sex Offense Cases: Relevance of Alleged Victim’s Past Sexual Behavior or Alleged Sexual Predisposition.
(a) Evidence Generally Inadmissible—The following evidence is not admissible in any civil or criminal proceeding involving alleged sexual misconduct except as provided in subdivisions (b) and (c):
(1) Evidence offered to prove any alleged victim engaged in other sexual behavior.
(2) Evidence offered to prove any alleged victim’s sexual predisposition.
(b) Exceptions—
(1) In a proceeding, the following evidence is admissible, if otherwise admissible under these rules:
(A) evidence of specific instances of sexual behavior by the alleged victim offered to prove that a person other than an accused was the source of semen, injury or other physical evidence;
(B) evidence of specific instances of behavior by the alleged victim with respect to the person accused of the sexual misconduct offered by the accused to prove consent or by the prosecution; and
(C) evidence the exclusion of which would violate the constitutional rights of the defendant.
(c) Procedure to Determine Admissibility—
(1) A party intending to offer evidence under subdivision (b) must—
(A) file a written motion at least 5 days before trial specifically describing the evidence and stating the purpose for which it is offered unless the court for good cause requires a different time for filing or permits filing during trial; and
(B) serve the motion on all parties and notify the alleged victim or, when appropriate, the alleged victim’s guardian or representative.
(2) Before admitting evidence under this rule the court must conduct a hearing which shall be closed. At this hearing, the parties may call witnesses, including the alleged victim, and offer relevant evidence. The victim must be afforded a reasonable opportunity to attend and be heard. In a case before a court-martial composed of a military judge and members, the military judge shall conduct the hearing outside the presence of the members pursuant to Article 39(a). The motion, related papers, and record of the hearing must be sealed and remain under seal unless the court orders otherwise.

