Will Avant-garde beauty code ever go out of fashion?

A question that has been hotly debated in top grade fashion circles from the days of their foundation. Certain styles do not have that capacity to be worn out after a couple of seasons or whenever a famous designer says so. Avant-garde is glamour, chick, smart and above all, timeless. You can be the beautiful lady from any echelon of society but once you know how to play the Avant-garde game all the curtains fall and you are represented as a glamorous diva. What does Avant-garde even mean? And how it came to be that this fashion code seemingly never