Buttoning and non-buttoning of the bottom button on the suit jacket and waistcoat

There are several explanations as to why some people leave the bottom button undone. It is said that King Edward VII of England, also known as Bertie, never fastened his bottom jacket button. Being rather overweight, he supposedly found it difficult to button up completely. However, this explanation seems the least credible.

Another theory suggests that dandies of the past often wore two waistcoats at once, making it impractical to fasten the bottom button of the top waistcoat. A third explanation is purely practical: walking is more comfortable with the bottom button undone, as it prevents the waistcoat from riding up. Likewise, leaving the bottom button of a jacket undone allows for a longer stride.

An interesting theory relates to students at the prestigious Eton College, who are recognised by their unfastened bottom waistcoat button. Their uniform belongs to the morning dress category. Looking at contemporary photographs of Eton students, one can see that they consistently leave this button undone.

In short, those knowledgeable about the culture of dressing are aware of this subtle detail, among many others. Therefore, one must not make a mistake.