The background of traditional contemporary Western dress codes as fixed in 20th century relied on several steps of replacement of preexisting formal wear, while in turn increasing the formality levels of the previously less formal alternatives. Thus was the case with the ceasing of the
justacorps, extensively worn from the 1660s until the 1790s, followed by the same fate of the 18th century
frock (not to be confused with frock
coat), in turn followed by the
frock coat.
Full dress, half dress, and undress Formal, semi-formal, and informal all have roots in 19th century customs subsequent to the replacement of the 18th century generic
justaucorps, and has remained fixed defined since the 20th century. The 19th century
frock coat rarely occurs except as formal alternative. For women, interpretations have fluctuated more dynamically according to
fashion. Before the modern system of
formal,
semi-formal, and
informal was consolidated in the 20th century, the terms were looser. In the 19th century, during the
Victorian and
Edwardian periods, the principal classifications of clothing were
full dress and
undress, and, less commonly the intermediate
half dress.
Full dress covered the most formal option: frock coat for
day wear, and
dress coat (
white tie) for
evening wear (sometimes with supplementary alternative being a full dress uniform independent of what time of the day). As such,
full dress may still appear in use designating
formal wear. When
morning dress became common (in the modern sense, using a morning tailcoat rather than a frock coat), it was considered less formal than a frock coat, and even when the frock coat was increasingly phased out, morning dress never achieved full dress status. Therefore, in the 21st century,
full dress often refers to white tie only. Today's semi-formal evening black tie (originally
dinner clothes) was initially described as
informal wear, while the "lounge suit," now standard business wear, was originally considered (as its name suggests)
casual wear.
Half dress, when used, was variously applied at different times, but was used to cover modern morning dress (the term
morning dress is fairly undescriptive and has not always meant modern morning dress).
Undress (not to be confused with
nudity) in turn was similarly loose in meaning, corresponding to anything from a
dressing gown to a
lounge suit or its evening equivalent of dinner clothes (now one of the more formal dress codes seen in many Western regions). ==References==