One meaning is that of when the seii taishogun (literally, "great general who subdues the barbarians") of the Muromachi bakufu made a political request to the Northern Court (the Imperial Court) on a particular issue.
室町幕府の征夷大将軍が北朝（朝廷）に対して特定の事項に関する政治的要請を行うこと。