Pennant

Pennon (or pennant), a narrow, tapering flag commonly flown by ships at sea:

Pennant (commissioning), the traditional sign of a warship, flown from its masthead while the ship is in commission

Broad pennant, flown from the masthead of a Royal Navy ship to indicate the presence of a commodore on board

Pennant (church), flown by navies during services on board ships

Pennant Measures, a stratigraphic division of the South Wales Coal Measures and including the Pennant Sandstone

Pennant number, a number used to identify ships by the modern Royal Navy and other navies of Europe and the Commonwealth