Nappies, also called diapers, are cloth or plastic-absorbent gel hybrid undergarments for the very young, and those with poor bladder control.

The basic principle of a diaper is that when the user needs to urinate or defecate it is easier to clean the user than the floor.

Cloth nappies are small squares of towelling which, when folded in a certain style, dependant on the sex of the child, are then fastened with a three inch metal pin. The main advantage of these nappies is that they cost less than disposable ones. The disadvantages range from the parent requiring black belt origami skills, to the disgusting task of washing soiled nappies so they can be reused.

In order to further the sales of plastic nappies, several companies have come up with newfangled features to add to their product. For example, breathable cores, customised absorbency locations, wetness indicators and refastenable tapes.

Disposable nappies are expensive, for no other reason than parents find them a necessity and so producers can charge as much as they like for them. These producers often play on maternal guilt in advertising their products, so parents dare not buy cheaper versions in case their child develops nappy rash and is taken into care.

The basic procedure for changing a diaper is as follows:

• Put on some sort of protective shield. The user doesn't care that you are putting a new diaper on them and will not wait until you have finished putting it on before processing more body waste. Should this occur, your shirt will serve the purpose nicely, if not suitably protected.

• Remove and dispose of the old diaper. Options for disposal include a diaper pail, or a toxic waste dump, as determined by local laws for your area.

• Clean the user, with either a moist washcloth, or sandblasting equipment, whichever is appropriate.

• Place the diaper under the user.

• Raise the clean diaper between the user's legs, and fasten it with anything that comes to hand, eg safety pins or refastenable tapes.

Be prepared to repeat this process again almost immediately, as the greatest laxative and diuretic for an infant is a clean diaper.

Spin-off products include training pants and disposable bedwetting underwear, which exist to lengthen the amount of time you need to purchase these products, and for no other reason.