The 523rd Tactical Wing was a Starfleet tactical wing that was involved in the Dominion War. It was comprised of mainly cruisers, frigates and Starfleet attack fighters. (LUG RPG: The Dominion War Sourcebook: The Fires of Armageddon)
In 2374, the 523rd was on patrol in the Svandroth system when it was ambushed by the Jem'Hadar. The wing's commander, Captain Jessica Murrow was killed when the USS Cibola was destroyed early in the engagement. The wing was rallied by Captain Daik'oth of the USS Novgorod and destroyed the ambushers before pushing on to the system the attacks had come from. The 523rd was able to take the Cardassian space station Taivok Nor by surprise and quickly disable it, gaining crucial intelligence on the Cardassian and Dominion forces.