Nomenclature issues in tennis

Inspired by a misunderstanding in a comment thread today, what are some confusing nomenclature issues in our sport? I'll start with a few:

Novak has won 24 grand slams, but never achieved the grand slam.

Stan won 11 ATP finals in a row, but only went to the ATP finals 4 times, and never got to the final of the ATP finals.

Indian Wells is a major tournament but not a Major tournament.

What are some others?