Well I'm not 100% sure about this acronym, but if it's true, then it's a very old one, but still frequently used!
Frutification
Under
Consent
of the
King
the story behind it (if true) would be that on the courts they had to place such a sheild on the door of the bedroom if wanting to presume the coresponding activity and that activity had to be allowed by the king, who could suposedly deny couples the right to have children even if merried.
