The Daughters of the American Revolution overwhelmingly adopted a rule yesterday requiring that DAR members give nine months' notice before filing suit against the organization.

Voting at its 95th Continental Congress, the DAR enacted the bylaw change, which would subject members who fail to wait the proscribed period to possible disciplinary action, including expulsion. The amendment would require that the member submit her grievance in writing to the DAR, and also would apply to lawsuits against DAR members related to their activities in the society.

The change comes as the DAR is fighting a suit in federal court by Faith K. Tiberio, a Sherborn, Mass., resident who was found guilty in October of "conduct injurious to the good name" of the DAR and two other charges for speaking out against a proposed bylaw amendment that she said would have made it more difficult for blacks to join the organization. The DAR board voted to reprimand Tiberio and then voted to suspend the reprimand.

The rule would not apply retroactively to Tiberio, but she said in a telephone interview yesterday that "this would be very helpful to them in the future." The nine-month wait, she said, "is like having a baby."

DAR President-General Sarah M. King said that fewer than 10 members voted against the change, out of a gathering of more than 2,000. She said the amendment was prompted by a desire "to do something to prevent the costs of litigation. We have lost our insurance and we felt this might improve our opportunities to reacquire insurance."

King said the change did not reflect an effort to squelch dissent within the organization. But she added, "I certainly hope that it will have the effect of making people think very hard before they resort to litigation."

She said that the nine-month wait "really isn't" overly long because the DAR's national board of management only meets a few times a year. "Nine months is needed," King said.