The following is a description on using the Clearquest 2003 windows application.

One of the most important rules in UI programming is that you should never rely on a right-click context menu as the only way to perform an action. This should only be thought of as a shortcut. Apple takes this paradigm to the extreme and only provides mice hardware with one button (but you can access a context menu via Option+click).

Clearquest is frustrating to use in other regards, but this was just the latest grumble about its user interface.