As the name indicates, side vents cut the slit on either sides and maintain the jacket from bunching or parting when you take a seat or put your hands into your pocket.
Know The Benefits Of Side Double Vents
A Guide to Understanding The Jacket & Suit Vents – A Hand Tailored Suit
Vanguard's guide to jacket vents - VANGUARD BESPOKE
Double Vents vs. Center Vent vs. No Suit Jacket Vents
What's a Plumbing Vent Pipe and How Does It Work? - Eyman Plumbing Heating & Air
The Anatomy Of A Suit Jacket: A Comprehensive Vocabulary
Should I wear Side or Center Vents? – The Dark Knot
Gas Fireplace Venting Explained
A Guide to Understanding The 3 Types of Suit Vents
29 Types of Suits for Men: The Guide to Suit Styles - Hockerty
Are Crawl Space Vents Necessary? Surprising Facts You Need to Know
A Guide To Suit Jacket Vents, Mens Suit Blog