Really cool, super helpful, but a guide to tipping that doesn't include bars as a separate category baffles me.

In the US bar tipping is extremely important, not remotely optional.

In the 90s I had my tips returned to me with irritation in bars and cafes in London. Can't remember what the deal was last time I went.

And I think this guide might could use some crowd sourcing? I tried to tip 10% in a restaurant in Milan a few years ago and my companion freaked out saying it was waaaaaay too much money.

I tried to tip a cab driver in Beijing about 7 years ago and she was old school, laughed, and gave it back.

These things are constantly changing so a guide is a wonderful thing, I am just a bit curious where the info is coming from.