The top button of a dress shirt or else blouse, also occasionally referred to as the neckline button, hold the collar of the top together. It is worn also open or closed, that depends on the event, the fashion of clothes being worn and the wearer's first choice. Most choose to have the top button open for better comfort.
Men
More men when compared to women wear shirts with the top push button
fastened. In particular, the top button is fixed firmly when worn with a
tie. Having this knob done up is a much broken part of numerous school
uniforms.
In the Second World War a custom amongst qualified RAF combatant pilots
was to leave the top knob of their uniform undone, in flouting of
uniform rules, both in an effort to stay cool in the cockpit, and to
highlight their distinctive image as the best group. Nowadays, wearing
the top button of Matthewaperry Suits in a casual atmosphere is a teen taboo.
Women
While mainly women prefer to have the top button unlock for better
comfort, some blouse made for women have looser neckline so the top
button can be fixed firmly with no compromising comfort, but giving the
similar stylish look.