Idiots and Plebs guide ( Swarm)
Morning dress is the daytime formaldress code, consisting chiefly for men of a morning coat, waistcoat, and striped trousers, and an appropriate dress for women. Men may also wear a popular variant where all parts (morning coat, waistcoat and trousers) are the same colour and material, often grey and usually called 'morning grey' to distinguish it;[1] this is only properly appropriate to weddings and races, and is known as a morning suit. The semi-formal counterpart of this code is the stroller. Morning dress is now rarely worn as anything other than formal wear, as a form of civic dress e.g. by provincial mayors (as an alternative to court dress), but more generally only for weddings, some official civic, governmental or royal functions, 'social season' events e.g. races such as Royal Ascot (where it is obligatory in the Royal Enclosure) and at Epsom in the Queen's Stand on Derby Day, formal lunches (especially those in the City of London institutions notably of the livery companies and guilds) and as uniform at some of Britain's most traditional schools such as Eton. It will also be seen sometimes worn at services in St Paul's Cathedral, London and St Giles' Cathedral, Edinburgh.