Special dispensation was a legal concept in which an action which was not normally sanctioned by the courts could be allowed due to extenuating circumstances.
Klingon law granted special dispensation to the female heir of a Great House to become the head of the family if the only possible male heir had died in an accident. However, were he to die in an honorable fight, the dispensation would not be granted, and the house would fall. Grilka faced this situation in 2371 when her husband Kozak died in Quark's bar, tripping and killing himself with his own knife, rather than being killed by Quark in self-defense. Tumek explained the concept to Quark, noting that D'Ghor wished the Ferengi to lie about the circumstances of the death so the house would have no heir. When Quark stood up to D'Ghor, calling the fight he would have had little more than an execution, his bravery was noted by the council, and they granted Grilka her husband's house. (DS9: "The House of Quark")
In 2374, despite Ferengi females usually not being allowed to leave Ferenginar, Ishka was granted special dispensation to do so by Grand Nagus Zek, so that she could have her ears raised. (DS9: "The Magnificent Ferengi")
In 2375, the Chief of Starfleet Operations granted Captain Benjamin Sisko special dispensation to change the name of the USS Sao Paulo to the USS Defiant (NX-74205). (DS9: "The Dogs of War")