I can confirm, if you don't you will receive angry emails.

Is it just Taiwan, or are there other countries in similar situations?

The ISO list shows Occupied Palestine in its preferred UN nomenclature, PALESTINIAN TERRITORY, OCCUPIED. This is a politically controversial area as well. How you should choose to identify the area depends in part on to which region you're targeting your site/app.

That's sad considering that Taiwan isn't even in the UN.