+<p>
+ The term <dfn>right-click</dfn> refers to the act of pressing and releasing
+ the <kbd class="mouse">Right</kbd> mouse button.
+ This action is used to pop up <dfn>context menus</dfn> (hence the term
+ "context click", which you will also see). It is also used by default in
+ combination with the shift key to delete objects within the editor
+ window.
+</p>
+<p class="note mac">
+ Some mice designed for use with Mac OS X may have only one button. By
+ convention, pressing and holding the Control key while clicking is
+ interpreted as a right-click by many application..
+</p>
+
+<h2>Middle Clicking</h2>
+<p>
+ A <dfn>middle-click</dfn> refers to the act of pressing and releasing the
+ <kbd class="mouse">Middle</kbd> mouse button. Not all all mice have a middle click button
+ (see the <a href="/setting-up-your-system/mouse/">Mouse</a> chapter for
+ details). Sometimes the scroll wheel acts as a clickable middle button.
+ This action is used for time-constrained region copying and mapping MIDI
+ bindings.
+</p>
+<p class="note">
+ Internally, your operating system may identify the mouse buttons as
+ <kbd class="mouse">Button1</kbd>, <kbd class="mouse">Button2</kbd>, and
+ <kbd class="mouse">Button3</kbd>, respectively. It may be possible to
+ invert the order of buttons to accommodate left-handed users, or to re-assign
+ them arbitrarily. This manual assumes the canonical order.
+</p>
+