The pocket square is a pocket handkerchief used for purely decorative purposes. It began life as a small square of material used for wiping one's nose, probably during the middle ages in England. The material from which they are made could vary according to their powers of absorption and the wealth of the owner, the more prosperous using silk.
They have been used for various purposes throughout their life ranging from the knotted handkerchief head protector favored by British holidaymakers to accompany their suspenders and rolled up trousers, to the white handkerchief signaling a surrender, to the placing of one on a judge's head during British rule in Hong Kong when passing the death sentence. However the simple use of the pocket handkerchief in modern times is purely decorative.
Tissue paper is nowadays used in preference to the handkerchief for hygiene purposes. This came about purely by accident when it was discovered that facial tissues were being used in place of the handkerchief.
When utilized for decorative purposes there are various ways of folding a handkerchief to place in the breast pocket of men's suits. Each method produces a different effect which can be chosen to match the occasion.
Folds are given flamboyant names such as the presidential, the one, two, three or four point folds and the puff. Each are designed to look different when placed in the top pocket.
It is very rare to wear a square in a business environment, due to the fact that it creates an informal impression. It is certainly the case that they are more often displayed at social events. However if worn to a board meeting, the more subtle and discreet square would be appropriate.
Never wear your pocket square or handkerchief hanging from the back pocket of your jeans by the way. The reason? It's used as a code within the gay community and the exact way its worn and the color indicates your preference.
Men's suits all require some accessories whether its simply the tie-pin or a cummerbund. The pocket square can be fashioned into an accessory to complement any suit or function.