MawB2
How do you define “formal casual” Grandad. To me they are mutually exclusive.
I understand smart casual, and “dress down Friday” - chinos and a button down shirt and no tie, but business dress is just that - a suit, surely?
Formal, suited and booted. Casual, sports jacket, trousers, always with turn ups and shirt with either a cravat or colourful bow tie. Dress down, similar trousers but worn with an Aloha shirt, I love the Hawaiian floral patterns.
All the above are worn with two tone shoes and Fair Isle socks. And topped off with a fedora hat.
Dress down and call it comfortable? Others might but I never could.