I have just read Michael Carter’s article in Fashion Theory, which explores ‘the limits of the linguistic model of clothing’. Carter contrasts two opposing views of clothes: that they are primarily functional, or, following Barthes, that they are primarily a system of communication. 
The article is most interesting in its exploration of functionality. At a basic level, clothes serve the practical purpose of protection (moral or physical). While one cannot deny that some garments were originally invested for the purposes of preservation or modesty, Carter argues that from the moment anyone witnesses a garment being worn, it ceases to be entirely functional, and takes on social or cultural meaning. The observation of a worn garment, even one whose initial purpose is practical, creates connotations that mean the garment must also express the kinds of messages described by Barthes.
Roger Caillois proposes that entirely utilitarian clothes do not exist. While there are many items that are entirely ornamental (stiletto heels, neckties, etc. ), there are none that are entirely functional . ‘The utilitarian role of an object’, he writes, ‘never completely justifies its form’. Design is never entirely about utility; there is always ‘an irrational residue’ or ‘stylistic surplus’. Carter uses as evidence the fact that not all garments with the same purpose are identical. Rather, there is variation in styles produced by different brands, even when their functional goals are the same. The modernist pursuit of utilitarian perfection was short lived, he argues, because it was an impossible dream.
Doctor Martins may be a good example of stylistic surplus. They were intended as primarily sturdy, protective footwear, but the fact that their visual appearance was distinct led to their adoption as fashion items, which in turn led to variations. Each of these variations is distinct in colour or style, not functionality.
Furthermore, argues Carter, this concern for aesthetic results in ‘small destructions of utility… where material is being diverted to the ornamental order’. In other words, functionality is often compromised for style.
The history of fashion has seen a progressive shift from functionality to decoration. Pockets, having been invented as a practical storage solution, have been developed into the defining aesthetic feature of numerous contemporary garments. Even the most functional elements of clothes have become ornamental. First, buttons became decorative, acting as substitutes for jewellery or medals. Much later, thanks in part to the deconstruction movement, zips became visible, oversized, and colourful. Fastenings are often entirely useless, unable to be fastened or unfastened, and added to a garment purely for aesthetic purposes.
I would also argue that there are examples of ornamental functionality – garments that have a functional aesthetic, but that are in reality functionless. Take, for example, the numerous uselessly overlaid pockets on the tulle vest below, which connote functionality but that primarily exist for aesthetic purposes.
Christopher Kane’s nuts and bolts are ornamentally functional too. They overtly duplicate the functionality of industrial bolts for decorative purposes, but they also preserve genuine functionality by acting as fastenings for adjoining panels of fabric. So, they have what Carter describes as ‘stylistic surplus’, but this particular surplus connotes extreme functionality.
 Michael Carter (2012), ‘Stuff and Nonsense: The Limits if the Linguistic model’ of Clothing’, Fashion Theory, vol. 16, issue 3, pp. 343-354.
 High heels, when originally worn by men, had the practical purpose of keeping feet safely in stirrups while riding. when worn for walking instead of riding, that function is obsolete.
 Roger Caillois (1990), The Necessity of Mind, Venice, CA: Lapis Press.