diff --git a/DOCS/mplayer.1 b/DOCS/mplayer.1
index acebe07227..f7c7e3c461 100644
--- a/DOCS/mplayer.1
+++ b/DOCS/mplayer.1
@@ -519,7 +519,8 @@ Specify frame/sec rate of subtitle file (float number)
 Currently useless. Same as \-audiofile, but for subtitle streams. (OggDS?)
 .TP
 .B \-subpos <0 \- 100> (usefull with -vop expand)
-Specify the position of subtitles on screen
+Specify the position of subtitles on the screen. The value is the vertical
+position of the subtitle in % of the screen height.
 .TP
 .B \-unicode
 Tells MPlayer to handle the subtitle file as UNICODE.