When wearing a 3-button suit, there are rules for which buttons to fasten. Here is your illustrated guide.
How To Button Your Suits, Jackets, Vests, Overcoats, & Tuxedo
The Sometimes, Always, Never 3-Button Suit Rule
Why You Should Never Use the Bottom Suit Button
When suiting up, always remember the 'sometimes-always-never' rule
Suit Button Rules: A Simple and Illustrated Guide
Suit Buttons: Everything You Need to Know - Hockerty
How To Button a Suit - Two Button Double-Breasted Suit - He Spoke
Three Button Suit- Brioni Suits, Suit Jacket, Single, 41% OFF
The reason you're not supposed to use the bottom button on suits
The Anatomy Of A Suit Jacket: A Comprehensive Vocabulary
How to Button Your Suit Jacket The Right Way