Best definition
Your Finest Attire
A term in used in modern wedding/party invitations to designate that the event is “black tie,” i.e. formal wear is

expected, tuxedoes for men, evening dresses for women. This term developed among children of the wealthy because while they did not want to embrace the terminology of their parents, they more than happy to embrace their parents customs.

When a wedding is to be a formal, black tie affair, the invitation will state, “Your Finest Attire for Friends, Family, Food, and Fun.”