I was recently told off in the lounge at the Fairmont Singapore (I'm not a fan of this place unlike many) for wearing sandals in the lounge alongside chinos and a formal but short sleeved shirt. I was told I needed to wear shoes and socks. The manner in which I was told this was far from pleasant so I asked why there was discrimination and inequality when almost every woman present was wearing sandals.

That met with the usual Singapore style response when they only know how to enforce rules but not what to do with a reasonable challenge to them. I said I would await a reasonable response before making any changes to my footwear and was not challenged again over the days until I left though I saw two other men chided. It's not where I usually stay in Singapore so I doubt I'll be back any time soon.