+<h3> CUSTOM COMMANDS</h3>
+<pre>
+ If the given command is not known to notmuch, notmuch tries to execute
+ the external <b>notmuch-<subcommand></b> in ${PATH} instead. This allows users
+ to have their own notmuch related tools to be run via the notmuch com‐
+ mand. By design, this does not allow notmuch's own commands to be over‐
+ riden using external commands.
+</pre>
+