Lubu 露布 (also called luquan 露權, luban 露版, chiban 赤板 or luzou 露奏) were ceremonial victory proclamations. The term is derived from a kind of unsealed letter reporting victory. From the Wei period 曹魏 (220-265) on, the document type was used during ceremonies of the announcement of a victory. The word lubu means approximately "public letter", written on silk cloth (bu 布). The Sui dynasty 隋 (581-618) began to use lubu proclamations as news sent to all parts of the empire. In the capital, the news of victory were announced outside Guangmen Gate 廣陽門. where all court officials had assembled. The news were read aloud by the Director of the Palace Secretariat (neishi ling 內史令). Similar ceremonies were held in all local administrations. From the Tang period 唐 (618-907) on, the arrival of a lubu report in the capital was received by the Vice Minister of War (bingbu shilang 兵部侍郎), and announced in public at the court by the Director of the Palace Secretariat (then called zhongshu ling 中書令).
The word lubu also referred to military announcements to or inside the army or related to military affairs, like military dispatches (xiwen 檄文). Because lubu letters were submitted to the throne, they belong to the types of up-going documents.
The word lubu was also generally used for unclosed or unsealed letters the content of which was positive and might thus be read by anyone, as for instance, the proclamation of amnesties or redemptions from punishment.