In 2366 Worf accepted discommendation before the Klingon High Council to hide the true traitor of Khitomer and keep the Empire stable.
In 2366 the Klingon High Council ruled that Worf's late father Mogh had betrayed the Khitomer outpost to the Romulans in 2346. Worf, joined by his brother Kurn, came to the Council to challenge the ruling. With Picard's help he found evidence that the real traitor had been Ja'rod, the father of the powerful councillor Duras.
Chancellor K'mpec admitted that the Council had blamed Mogh because exposing the Duras family could have caused a civil war. To protect the Empire, Worf chose to accept discommendation, a formal shunning, while keeping the truth secret. He would win his family's honor back during the Klingon Civil War.