its apparel.
in the area of apparel there is mens/womes/childrens/etc
a wedding dress would obiously be womens
then there is like all the streetwear/formalwear/specialoccasion/swimwear/etc
and the wedding dress would be special occasion
your dress could be put in costume if you say that its for a fancy dress ball or something. if its for a formal dinner/fashion show its really an apparel item.
theres nothing wrong with putting your dress under apparel instead of costume. if the markers dont see enough justification for you...
the functional properties of a textile art item depends on the actual item. firstly the function of a textile art is to look good and express your theme/concept/message in a creative way. if your textile art is something that is wearable, construction features could be important (depending on...