Belt loops were meant to be used on suit pants

Update:10 Oct 2019
Summary:

Men's trousers are designed in two different ways: some […]

Men's trousers are designed in two different ways: some have belt loops for wearing with a belt, and some have side tabs for tightening/adjusting the waist when not wearing a belt. The choice is up to you.In certain cases belt loops are not necessary.The four buttons on the sleeves of suit jackets are explained in a couple of ways. The story we hear most often (which I rather doubt) is that they were put there in medieval times to prevent men from boorishly wiping their noses on their sleeves.

The much more likely reason was that all men wore their jackets no matter what they were doing. Whether reading a book, climbing a mountain, or merely working in their own garden, they kept their jackets on. Thanks to the functioning sleeve buttons, a man could just unbutton and roll up the sleeves without removing his jacket, thus, preventing it from getting dirty. In those days, taking one's jacket off in public was akin to stripping down to his underwear.The primary reason is if a man is a regular wearer of  braces the upscale  and British  term for suspenders that are attached to trousers with buttons. Those tacky metal clip-on suspenders that some men wear are designed for wear on overalls or little boys' pants; they don't even merit the term "braces."

Well-dressed men who wear braces on a regular basis have a tailor sew six buttons inside the waistbands of their suit trousers; they then also have the unnecessary belt loops removed.Better suits and custom-made suits are often made with small adjustable side tabs of fabric on the waistbands of the trousers. These adjust the waist size, making a belt unnecessary. Side tabs are a matter of personal preference. A lot of men like the resulting clean look and the trim effect. Others feel "undressed" without a belt, and choose to have belt loops and a belt, rather than side tabs, even on their custom suits.In either case, you should decide which is your personal dressing style; then choose one or the other.

Do not wear a belt and braces; do not have belt loops and side tabs on the same pair of trousers. In other words, belt loops have a purpose; they are there to hold your belt in place. They are not one of those sartorial touches that are there for show Some clothing items parts of clothing are real and useful, while some are just for show. Many aspects of men's clothing are relics from the past, based on history rather than need. And a few are somewhere in between, since they once had a purpose and now no longer do. Here are a few examples Neckties started out as decorative scarves that imperial Roman legionnaires wore tucked into their armor or simply tied. The scarves were not worn by the general public but only by soldiers as a badge of honor.

Custom Suspenders