Clarify docs for --comment slightly.

svn path=/trunk/vorbis-tools/; revision=4091

oggenc/man/oggenc.1

@@ -155,7 +155,8 @@ gives a literal %.
 Add the string
 .I comment
 as an extra comment.  This may be used multiple times, and all
-instances will be added to each of the input files specified.
+instances will be added to each of the input files specified. The argument
+should be in the form "tag=value".
 
 .IP "-a artist, --artist artist"
 Set the artist comment field in the comments to

oggenc/oggenc.c

@@ -420,7 +420,8 @@ static void usage(void)
         "                      Default settings for the above two arguments are platform\n"
         "                      specific.\n"
 		" -c, --comment=c      Add the given string as an extra comment. This may be\n"
-		"                      used multiple times.\n"
+		"                      used multiple times. The argument should be in the\n"
+        "                      format \"tag=value\".\n"
 		" -d, --date           Date for track (usually date of performance)\n"
 		" -N, --tracknum       Track number for this track\n"
 		" -t, --title          Title for this track\n"