The black lounge suit (UK), stroller (U.S.), or Stresemann, is a men's day attire semi-formal intermediate of a formal morning dress and an informal lounge suit; comprising grey striped or checked formal trousers, but distinguished by a conventional-length lounge jacket, single- or double-breasted in black, midnight blue or grey. This makes it largely identical to the formal morning dress from which it is derived, only having exchanged the morning coat with a suit jacket, yet with equivalent options otherwise, such as necktie or bowtie for neckwear, a waistcoat, French cuffs dress shirt of optional collar type, and black dress shoes or dress boots. The correct hat would be a semi-formal homburg, bowler, or boater hat. Just as morning dress is considered the formal daytime equivalent of formal evening attire dress coat i e. white tie, so the stroller is considered the semi-formal daytime equivalent of the semi-formal evening attire dinner jacket, i.e. black tie. Unlike other dress codes, there is no clear equivalent for women, though typical morning dress and cocktail dress have both been identified as alternatives.

Morning dress, also known as formal day dress, is the formal Western dress code for day attire, consisting chiefly of, for men, a morning coat, waistcoat, and formal trousers, and an appropriate gown for women. Men may also wear a popular variant where all parts are the same colour and material, often grey and usually called "morning suit" or "morning grey" to distinguish it; considered properly appropriate only to festive functions such as summer weddings and horse races, which consequently makes it slightly less formal. The correct hat would be a formal top hat, or if on less spacious audience settings optionally a collapsible equivalent opera hat.