Make the manpage of su clearer

diff --git a/login-utils/su.1 b/login-utils/su.1
index 6ab3e4a77e4ba2bfbb069d046661bb0eebf1bc43..3a732799a70cefa5c3b5cd43907714688123abf4 100644 (file)
--- a/login-utils/su.1
+++ b/login-utils/su.1
@@ -8,10 +8,17 @@ su \- run a command with substitute user and group ID
 .B su
 allows to run commands with a substitute user and group ID.
 .PP
-When called without arguments,
+When called with no
+.IR user
+specified,
 .B su
 defaults to running an interactive shell as
 .IR root .
+When
+.IR user
+is specified, an additional
+.IR argument
+can be supplied, in which case it is passed to the shell.
 .PP
 For backward compatibility,
 .B su