Double standard
A double standard was a rule which a group applied to certain individuals but not others.
In 2152, afflicted with Pa'nar Syndrome, T'Pol refused to confirm that she had been mind melded with against her will, as she felt to do so would aid the Vulcans's double standard of "condemn(ing) the infected when they meld by choice and sympathize(ing) with them when they don't". (ENT: "Stigma")