A strike fleet as a military unit in the Dominion fleet organisation. Strike fleets are groupings of between 100 and 300 starships (some fleets included Cardassian warships) formed for a particular purpose from a Dominion division. As such strike fleets have no permanent designation as they are forced as required. Command of a strike fleet is usually given to a Chelek'toran, though if the mission is of great enough importance a Sadok'toran will take command of the fleet.
Strike fleets are given a number/letter designation when formed such as 7-Gamma-F. In an effort to track fleet moments Starfleet Intelligence would assign the strike fleet a name based on where it was first encountered, so 7-Gamma-F could be referred to as the Betazed-12 fleet given it was initially encountered in the system. (The Dominion War Sourcebook: The Fires of Armageddon)