+.BR --clean=git | -wg
+The source tree should be cleaned, before building a source package
+with one of the build options, using
+.BR "git clean -xdf" .
+This will delete all files which are not tracked by git.
+.TP
+.BR --clean=none | -wn
+Do not clean the tree before building a source package. If there are
+files which are not in git, a subsequent dgit push will fail.
+.TP
+.BR --clean=dpkg-source | -wd
+Use dpkg-buildpackage to do the build, so that the source package
+is cleaned by dpkg-source running the package's clean target.
+This is the default. It requires the package's build dependencies.
+.TP