docs: document braille display mode

diff --git a/man/mtr.8.in b/man/mtr.8.in
index 7a70065e2770f05158d6d7ff8d169e44b6cdefd0..3edbf2917a49db223abe39d05daaf31798cba995 100644 (file)
--- a/man/mtr.8.in
+++ b/man/mtr.8.in
@@ -228,7 +228,8 @@ clears spurious error messages that may overwrite other parts of the display.
 Use this option to select the initial display mode: 0 (default)
 selects statistics, 1 selects the stripchart without latency
 information, and 2 selects the stripchart with latency
-information.
+information.  If braille graphs were enabled at build time and wide
+curses support is available, 3 selects a braille stripchart.
 In stripchart modes,
 .B ?
 marks a probe that has not received a response, and