Can tags have hierarchy?

Does anyone have experience working with nested tags? I could not find any websites that allow users to have hierarchies in their tags (equivalent to non-mutually exclusive categories). Is it a bad practice in general? If so,…
Should I use Yes/No or Ok/Cancel on my message box?

Semantically, the Yes/No buttons are roughly equivalent to the Ok/Cancel buttons, but in general what would you recommend to use? Should I always use Yes/No or always use Ok/Cancel? Or does it depend on the case?
Should I use Yes/No or Ok/Cancel on my message box?

Semantically, the Yes/No buttons are roughly equivalent to the Ok/Cancel buttons, but in general what would you recommend to use? Should I always use Yes/No or always use Ok/Cancel? Or does it depend on the case?
What do you put in a country list for countries with more than one common name?

I’m from England, which means in drop-down lists I have to search for United Kingdom, then England, then Great Britain… it’s generally the UK, but it does vary from site to site. What is the best practice for cases like thi…
What is the difference between wireframing and prototyping

What is the difference between wireframing and prototyping? Am I right to think that prototypes should be interactive and wireframes should be static?