+.. el:define-key:: <tab>
+
+ Cycle visibility state of the current message's tree.
+
+.. el:define-key:: <M-tab>
+
+ Cycle visibility state of all trees in the buffer.
+
+The behaviour of this minor mode is affected by the following
+customizable variables:
+
+.. el:defcustom:: notmuch-tree-outline-enabled
+
+ |docstring::notmuch-tree-outline-enabled|
+
+.. el:defcustom:: notmuch-tree-outline-visibility
+
+ |docstring::notmuch-tree-outline-visibility|
+
+.. el:defcustom:: notmuch-tree-outline-auto-close
+
+ |docstring::notmuch-tree-outline-auto-close|
+
+.. el:defcustom:: notmuch-tree-outline-open-on-next
+
+ |docstring::notmuch-tree-outline-open-on-next|