Improve documentation of \n[.U].

1 files changed, 3 insertions, 2 deletions

diff --git a/doc/groff.texinfo b/doc/groff.texinfo
index d37690a2..83bec112 100644
--- a/doc/groff.texinfo
+++ b/doc/groff.texinfo
@@ -6300,8 +6300,9 @@ Horizontal resolution in basic units.
 @cindex mode, safer
 @cindex unsafe mode
 @cindex mode, unsafe
-If @code{gtroff} is called with the @option{-U} command line option, the
-number register @code{.U} is set to@tie{}1, and zero otherwise.
+If @code{gtroff} is called with the @option{-U} command line option to
+activate unsafe mode, the number register @code{.U} is set to@tie{}1, and
+to zero otherwise.
 @xref{Groff Options}.
 
 @item \n[.V]