Is the first row of buttons on a double breasted jacket functional

Is the first row of buttons on a double breasted jacket functional

Suit style 3: The double breasted – Permanent Style

1930's bespoke Savile Row double breasted dinner jacket size 44

Variations on the Double-Breasted Jacket: Buttons, Wrap and Lapel

Is the first row of buttons on a double breasted jacket functional or purely ornamental? - Quora

How to add a personal touch to your jacket through customization or embellishments - Quora

The rules and how to break them 8: Button a DB – Permanent Style

What button should I close when wearing a three buttoned jacket? - Quora

What button should I close when wearing a three buttoned jacket? - Quora