Retro is a culturally outdated or aged style, trend, mode, or fashion, from the overall post-modern past, that has since that time become functionally or superficially the norm once again. The use of "retro" style iconography and imagery interjected into post-modern art, advertising, mass media, etc. It generally implies a vintage of at least fifteen or twenty years. For example, clothing from the 1970s, 1980s or 1990s could be retro.