diff --git a/usr.bin/comm/comm.1 b/usr.bin/comm/comm.1
index 0a34160c0e7..2ae526967a7 100644
--- a/usr.bin/comm/comm.1
+++ b/usr.bin/comm/comm.1
@@ -61,11 +61,13 @@ The filename ``-'' means the standard input.
 The following options are available:
 .Bl -tag -width indent
 .It Fl 1
-Suppress printing of column 1.
+Suppress printing of column 1, lines only in 
+.Ar file1 .
 .It Fl 2
-Suppress printing of column 2.
+Suppress printing of column 2, lines only in
+.Ar file2 .
 .It Fl 3
-Suppress printing of column 3.
+Suppress printing of column 3, lines common to both.
 .It Fl i
 Case insensitive comparison of lines.
 .El