For weddings in heat and humidity: Men can go for lightweight suits in light, summer-friendly colors like beige, light blue, soft grey or light green materials that breathe. Just a collared dress shirt in these colours and suit jacket will be suitable. Depending on dress code a tie may not be needed or even a jacket, so a waistcoat could add a bit of flair. Avoid darker, heavier fabrics. Recommended Fabrics: Cotton or linen only. These fabrics allow air flow and wick moisture away from the body. Accessories: A floral or pastel tie or floral print pocket square can add a bit of fun. Footwear: Loafers or light brogues are ideal for summer, especially in breathable materials. Edit to add: some images of ideas here https://imgur.com/a/gjzSXnB More on reddit.com

Standalone, the outfit looks good, you pull it all off really well. That said, technically the “rules” for formal are pretty cut and dry, and this is 100% not formal. I’d say it’s not even semi formal. If the host or whatever doesn’t care, then great, more power to you. But I’ve seen people be real assholes about sticking to dress code, just as a heads up if you try to wear this to another formal event. More on reddit.com

To me, semi formal means a man wears a suit and tie, and a woman wears a cocktail type dress that need not be especially flashy. Dress shoes, although the woman can obviously wear low heels or flats if that's what she is comfortable in. Again, they need not be super fancy but just not running shoes or something of that sort. Exception would be if there are foot or mobility problems involved, in which case you wear the footwear that meets your needs. More on reddit.com

sounds like they want to say no gym casual. The one on the left is definitely not what you would call semi-formal. More on reddit.com