docs: explain stripchart markers

diff --git a/man/mtr.8.in b/man/mtr.8.in
index 5101094497b275ad37acf111483359092aea9ee4..e34bef99392c1d20bbc9776587b37f9cf0dcd7a2 100644 (file)
--- a/man/mtr.8.in
+++ b/man/mtr.8.in
@@ -221,6 +221,11 @@ 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.
+In stripchart modes,
+.B ?
+marks a probe that has not received a response, and
+.B >
+marks a response slower than the largest latency bucket shown in the scale.
 .TP
 .B \-g\fR, \fB\-\-gtk
 Use this option to force