The D.C. Court of Appeals has ruled that testimony about a rape victim's reputation for promiscuity with other men cannot be admitted as evidence in the trial of a man accused of raping her.

In its decision, the three-judge panel noted a trend in other jurisdictions where courts have concluded that a women's prior conduct with persons other than the defendant involved in a raped case is not admissible "to prove that she consented to sexual intercourse with the accused."

The ruling upheld the conviction of Spencer McLean, who was found guilty in January, 1976, of raping a 17-year-old woman.

In a footnote, the court noted that testimony as to the victim's conduct with the defendant prior to the offense would be admissible where there is a question of identity at trial or where the prosecution contends the particular instance constituted rape and not a consenting act.

"We deem a woman's reputation for unchasity to be of very slight probative value since it is neither relevant to her credibility as a witness, nor material on the issue whether on the occasion of the alleged crime she consented or was forced to submit to an act of intercourse," the court said.

The opinion was written by Associate Judge John W. Kern III, with Judged Frank Q. Bebecker and J. Walter Yeagley, concurring.

Feminist groups long have held that a woman's sexual relations with other men ar irrelevant in a rape case.

Moreover, they have contended that testimony should be limited to the facts fo the case and references to prior acts with the defendant excluded.

The decision by the Appeals Court, handed down yesterday, "is in the right direction but it doesn't go far enough," Ellie Smeal, president of the National Organization for Women.

The Appeals Court ruling governs all rape trials in the District of Columbia and could be relied on for support in cases in other jurisdictions. The appellate court decision upheld a ruling by D.C. Superior Judge Norma Holloway Johnson.

The APpeals Court said that it was not convinced that in rape cases, the victim's credibility as a witness "must be weighed by the jury on evidence directly related to whether (the victim) consented to a sexual act with the accused and not on evidence of her prior sexual relations with others, or her reputation for unchastity."

The Appeals Court took note of what it called the "sensitivity" of a Utah court, which found that many rapes go unreported because victim's are fearful that they will be subjected to "humiliation" from inquiry into their personal lives - in effect putting them on trial and not the alleged assailant.

"We agree and hasten to add that these 'negative factors' serve well as justification for excluding evidence of complainant's prior sexual relations with other men," the Appeals court said.

While the Utah court allowed the admission of reputatio testimony on the issue of consent, the D.C. Court of Appeals said it was not persuaded that in the McLean case, the testimony's value as to resolving the question of consent outweighed its prejudicial effect on the jury.

I found that such testimony about a victim's side issues that are "nearly impossible to rebut," and diverts the jury's attention from the principal issues at trial.

Reputation testimony should not be admitted except in the "most unusual cases" where the need to hear such evidence is precisely demonstrated and outweights its prejudicial effect, the court said. Such cases would for example be where the defendant alleges the woman consented to an act of prostitution or to rebut prosecution evidence about the women's chastity, the court said.