Aviso

A French aviso colonial of the Bougainville class
The Portuguese aviso NRP Afonso de Albuquerque, in 1932

An aviso was originally a kind of dispatch boat or "advice boat", carrying orders before the development of effective remote communication.

The term, derived from the Portuguese and Spanish word for "advice", "notice" or "warning", an aviso, was later adopted by the French and Portuguese navies to classify their medium-sized warships designed for colonial service. The term continued to be used in the French Navy to classify the D'Estienne d'Orves-class patrol frigates until 2012, when the remaining ships of the class were reclassified as offshore patrol ships. It is equivalent to the modern use of "sloop" in other countries.