Formality is a continuum, not a definate style, that differs from one social circle to another. Each of us can describe what we consider to be “appropriate everyday wear”, “sloppy not-to-be-seen-in-public wear”, and “Man, I-only-get-this-dressed-up-to-see-the-Queen wear”. In the world of traditional etiquette, these are well-defined:
– “formal” means black tail-coat with matching trousers with a white piquet shirt with stand-up collar worn with a white bow-tie and white vest (in the evening) or a cutaway morning-coat with striped trousers and white shirt worn with a Windsor or Ascot tie (before six o’clock);
– “semi-formal” means a dinner-jacket with matching trousers and white shirt with fold-down collar worn with a black bow-tie (in the evening) or stroller-jacket with matching trousers and white shirt with fold-down collar worn with four-in-hand tie (before six o’clock);
– “informal” means a two- or three-piece business suit with windsor or four-in-hand tie; and
– “casual” means sports-jacket or blazer with contrasting trousers.
For ladies the equivalents are
– full-length evening dress with jewels and gloves (in the evening) or silk tea-length solid-coloured dress with pearls, hat and gloves (before six);
– “semi-formal” being cocktail dress or evening dress with shoulders covered and fascinator and/or costume jewelry (in the evening) or tea-length or shorter silk or other tailored fabric dress with pearls, hat and gloves (before six);
– “informal” being business suit or tailored dress with pearls or beads; and
– “casual” being a sports dress or shirt-waist dress.
Wearing something inappropriate — like wearing a “tux” before six o’clock or wearing a full-length dress with train during the day — is none of the above, and just doesn’t happen. It certainly isn’t considered formal.
The problem with weddings is, that outside of the world of formal etiquette where most wedding guests really live, the terms are not that well defined. For my rodeo-cowboy nephews, “formal” means new jeans, a cowboy hat that isn’t used around the barns or corrals, the engraved silver belt-buckle, a shirt with pearl snaps and the “good” boots. For my urban teen-age grandnieces, a strapless silk mini-dress with fancy stockings and spikey high heels is equally appropriately formal for day or evening, church or club; whereas their everyday “informal” includes yoga-pants and frayed hoodies that I wouldn’t even wear when NOT in public. Even here on the etiquette board, many people who say they are looking for “formal” would be absolutely delighted if all their gentlemen guests showed up in dark three-piece business suits (which would properly be “informal”). Most women I know have resorted to the general standard that anything with a skirt is formal, and anything worn with pearls is passe.
If it is any consolation, although the Queen (then Princess Elizabeth) could have confidence back in 1947 that her guests would figure out how to dress themselves properly for a formal day-time church event, by the time Prince Charles married in 1981 even royal wedding invitations acknowledged that modern people need to be told how to dress. His invitations, like those of his son last April, included the annotation “Dress: Uniform, Morning Coat, or Lounge Suit” on the lower right corner. If the Queen does it, it is considered acceptable in all her realms (alas). But I heartily support any American bride who chooses to hold to the standard that guests should be trusted with their own apparel.