Prohibition against use of a person's character, propensity, or disposition to show the person's conduct on a particular occasion; i.e., the prohibition against "circumstantial" character evidence, or the prohibition against "circumstantial" use of a person's character or propensity.

Cf. Pennsylvania v. Ritchie, 480 U.S. 39, 58 (1987) (accused charged with sexual offenses against his daughter; held, accused had constitutional right "to have the CYS [Children and Youth Services] file [which was confidential under state law] reviewed by the trial court to determine whether it...A nonconstitutional privilege sometimes must yield to a criminal defendant's Sixth Amendment right to confront and cross-examine an adverse witness in a criminal trial. A nonconstitutional privilege privilege may have to yield to a criminal defendant's Confrontation Right when the privilege shields evidence or facts (particularly evidence or facts showing bias) that have significant probative value on the credibility of an adverse witness in a criminal trial who testifies about material facts in issue.

Fed. R. Evid. 4129c) ("(1) A party intending to offer evidence under subdivision (b) must -- (A) file a written motion at least 14 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;...If a party in a case involving a charge or claim of sexual assault intends to offer evidence of the sexual disposition of the victim or the sexual conduct of the victim on other occasions to show the alleged victim's consent to sexual relations with the party charged with sexual assault, the offeror may be required by a rape shield law to give advance notice of the offeror's intent to do so.

Fed. R. Evid. 404(a)(2) ("In a criminal case, and subject to the limitations imposed by Rule 412, evidence of a pertinent trait of character of the alleged victim of the crime offered by an accused" is admissible.).In a criminal trial accused may offer a pertinent character trait of a victim to show the victim's conduct on a particular occasion; i.e., accused may use victim's character "circumstantially," as "circumstantial" evidence of victim's conduct on a specific occasion.