Most single-breasted suits have two or three buttons, and one or four buttons are unusual. It is rare to find a suit with more than four buttons, although zoot suits can have as many as six or more due to their longer length. There is also variation in the placement and style of buttons, since the button placement is critical to the overall impression of height conveyed by the jacket. The centre or top button will typically line up quite closely with the natural waistline.
Double-breasted jackets have only half their outer buttons functional, as the second row is for display only, forcing them to come in pairs. Some rare jackets can have as few as two buttons, and during various periods, for instance the 1960s and 70s, as many as eight were seen. Six buttons are typical, with two to button; the last pair floats above the overlap. The three buttons down each side may in this case be in a straight line (the 'keystone' layout) or more commonly, the top pair is half as far apart again as each pair in the bottom square. A four-button double-breasted jacket usually buttons in a square. The layout of the buttons and the shape of the lapel are co-ordinated in order to direct the eyes of an observer. For example, if the buttons are too low, or the lapel roll too pronounced, the eyes are drawn down from the face, and the waist appears larger.
The custom that a man's coat should button "left side over right", anecdotally originates in the use of the sword, where such cut avoided catching the top of the weapon in the opening of the cloth (since the sword was usually drawn right-handed). Women's suits are buttoned "right side over left". A similar anecdotal story to explain this is that women were dressed by maids, and so the buttons were arranged for the convenience of their, typically, right-handed servants; men on the other hand dressed themselves and so the buttons were positioned to simplify that task.
A notched lapel
A peaked lapel
A shawl lapel
The jacket's lapels can be notched (also called "stepped"), peaked ("pointed"), shawl, or "trick" (Mandarin and other unconventional styles). Each lapel style carries different connotations, and is worn with different cuts of suit. Notched lapels are only found on single-breasted jackets and are the most informal style. Double-breasted jackets usually have peaked lapels. Shawl lapels are a style derived from the Victorian informal evening wear, and as such are not normally seen on suit jackets except for dinner suits.
In the 1980s, double-breasted suits with notched lapels were popular with power suits and the New Wave style.
In the late 1920s and 1930s, a design considered very stylish was the single-breasted peaked lapel jacket. This has gone in and out of vogue periodically, being popular once again during the 1970s, and is still a recognised alternative. The ability to properly cut peak lapels on a single-breasted suit is one of the most challenging tailoring tasks, even for very experienced tailors.
The width of the lapel is a varying aspect of suits, and has changed over the years. The 1930s and 1970s featured exceptionally wide lapels, whereas during the late 1950s and most of the 1960s suits with very narrow lapels—often only about an inch wide—were in fashion. The 1980s saw mid-size lapels with a low gorge (the point on the jacket that forms the "notch" or "peak" between the collar and front lapel). Current (mid-2000s) trends are towards a narrower lapel and higher gorge.
Lapels also have a buttonhole, intended to hold a boutonnaire, a decorative flower. These are now only commonly seen at more formal events. Usually double-breasted suits have one hole on each lapel (with a flower just on the left), while single-breasted suits have just one on the left.
Most jackets have a variety of inner pockets, and two main outer pockets, which are generally either patch pockets, flap pockets, or jetted pockets. The patch pocket is, with its single extra piece of cloth sewn directly onto the front of the jacket, a sporting option, sometimes seen on summer linen suits, or other informal styles. The flap pocket is standard for side pockets, and has an extra lined flap of matching fabric covering the top of the pocket. A jetted pocket is most formal, with a small strip of fabric taping the top and bottom of the slit for the pocket. This style is most often on seen on formalwear, such as a dinner jacket.
In addition to the standard two outer pockets, some suits have a third, the ticket pocket, usually located just above the right pocket and roughly half as wide. While this was originally exclusively a feature of country suits, used for conveniently storing a train ticket, it is now seen on some town suits. Another country feature also worn sometimes in cities is a pair of hacking pockets, which are similar to normal ones, but slanted; this was originally designed to make the pockets easier to open on horseback while hacking.
Suit jackets in all styles typically have three or four buttons on each cuff, which are often purely decorative (the sleeve is sewn closed and cannot be unbuttoned to open). Five buttons are unusual and are a modern fashion innovation. The number of buttons is primarily a function of the formality of the suit; a very casual summer sports jacket might traditionally (1930s) have had only one button, while tweed suits typically have three and city suits four. In the 1970s, two buttons were seen on some city suits.Today, four buttons are common on most business suits and even casual suits.
Although the sleeve buttons usually cannot be undone, the stitching is such that it appears they could. Functional cuff buttons may be found on high-end or bespoke suits; this feature is called a surgeon's cuff. Some wearers leave these buttons undone to reveal that they can afford a bespoke suit, although it is proper to leave these buttons done up.Modern bespoke styles and high end off-the-rack suits equipped with surgeon's cuffs have the last two buttons stitched off-centre, so that the sleeve hangs more cleanly should the buttons ever be undone.
A cuffed sleeve has an extra length of fabric folded back over the arm, or just some piping or stitching above the buttons to allude to the edge of a cuff. This was popular in the Edwardian era, as a feature of formal wear such as frock coats carried over to informal wear, but is now rare.
A vent is a slit in the bottom rear (the "tail") of the jacket.Originally, vents were a sporting option, designed to make riding easier, so are traditional on hacking jackets, formal coats such as a morning coat, and, for reasons of pragmatism, overcoats. Today there are three styles of venting: the single-vented style (with one vent at the centre); the ventless style; and the double-vented style (one vent on each side). Vents are convenient, particularly when using a pocket or sitting down, to improve the hang of the jacket, so are now used on most jackets. Ventless jackets are associated with Italian tailoring, while the double-vented style is typically British.(This is not the case with all types of jackets. For instance, dinner jackets traditionally take no vents.)
Suit jackets with belts on them became popular after World War I, especially on the exaggerated "jazz suits" which were popular in 1920 and 1921. After 1921, a more subdued style prevailed in which the belt was placed solely on the back of the coat, a half-belted back. This continued on many suit coats throughout the 1920s and early 1930s, usually on very fashionably made suits for the young. This style made a brief comeback in the 1970s when some suit coats again featured belts on the back.