A buyruldu was a decree issued by a high-ranking official and passed to lower-ranking ones in the Ottoman Empire. It literally means "It was decreed" in Turkish, derived from the Turkish verb buyur- (to decree).
A buyruldu could be issued by the Grand Vizier or other ministers such as defterdar in the capital; or by the beylerbey in the country. The decrees issued by the sultan were called ferman.
References
Buyruldu Wikipedia(Text) CC BY-SA