man page: Update the -ttt and -ttttt options sections
The delta is printed with microsecond or nanosecond resolution depending
on the --time-stamp-precision option (default is microsecond resolution).
diff --git a/tcpdump.1.in b/tcpdump.1.in
index 6d87306..d11424e 100644
--- a/tcpdump.1.in
+++ b/tcpdump.1.in
@@ -684,16 +684,20 @@
fractions of a second since that time, on each dump line.
.TP
.B \-ttt
-Print a delta (micro-second resolution) between current and previous line
-on each dump line.
+Print a delta (microsecond or nanosecond resolution depending on the
+.B \-\-time\-stamp-precision
+option) between current and previous line on each dump line.
+The default is microsecond resolution.
.TP
.B \-tttt
Print a timestamp, as hours, minutes, seconds, and fractions of a second
since midnight, preceded by the date, on each dump line.
.TP
.B \-ttttt
-Print a delta (micro-second resolution) between current and first line
-on each dump line.
+Print a delta (microsecond or nanosecond resolution depending on the
+.B \-\-time\-stamp-precision
+option) between current and first line on each dump line.
+The default is microsecond resolution.
.TP
.B \-u
Print undecoded NFS handles.
