Pennant can be of many types:-
A usually narrow, tapering flag most commonly flown by ships at sea and sometimes called "pendants". Navies use a variety of pennants.
A commissioning pennant, the traditional sign of a warship, flown from its masthead while the ship is in commission. A broad pennant, flown from the masthead of a Royal Navy ship to indicate the presence of a commodore on board. A church pennant, flown by navies during church services on board ships. In the United States Navy it is flown above a flag of national colors.
In team sports, a commemorative flag displayed or flown by a league-winning team. The last few weeks of the regular American professional baseball season, for instance, are known as the "pennant race". A reference to the pennant-shaped "No Passing Zone" traffic sign found in the United States, used to indicate the start of a two-lane highway where vehicles traveling in the same direction are not permitted to pass each other. See also Prohibitory traffic sign.