diff --git a/documents/ros-use.1 b/documents/ros-use.1
index 7dc8ad3..13a7c14 100644
--- a/documents/ros-use.1
+++ b/documents/ros-use.1
@@ -1,13 +1,28 @@
 .TH "ros-use" "1" "" "" ""
 .nh \" Turn off hyphenation by default.
 .PP
-ros\-use \-
+ros\-use \- sets the default implementation used by roswell
 .SH synopsis
 .PP
-\f[B]ros [options] use\f[] args...
+\f[B]ros [options] use\f[] impl[/version]
+.PP
+impl : The name of an implementation which is already installed.
+New implementations can be downloaded by \f[I]ros\-install\f[](1).
+The list of installed implementations is available in
+\f[I]ros\-list\f[](1).
+.PP
+version: : The version specifier.
+The string representation of the version (e.g.
+.) depends on each implementation and roswell generally follows the
+representation used by the implementation.
 .SH description
+.PP
+\f[C]ros\ use\f[] sets the default implementation used by roswell.
+It is by default \f[C]sbcl\-bin\f[], which is a stable and well\-tested
+version of sbcl.
 .SH SEE ALSO
 .PP
-\f[I]ros\f[](1)
+\f[I]sbcl\f[](1), \f[I]ros\f[](1), \f[I]ros\-install\f[](1),
+\f[I]ros\-list\f[](1)
 .SH AUTHORS
 SANO Masatoshi.
diff --git a/documents/ros-use.html b/documents/ros-use.html
index 1440c49..b544bce 100644
--- a/documents/ros-use.html
+++ b/documents/ros-use.html
@@ -18,9 +18,11 @@
 <li class="author">SANO Masatoshi</li>
 </ul>
 </header>
-<p>ros-use -</p>
+<p>ros-use - sets the default implementation used by roswell</p>
 <h1>synopsis</h1>
-<p><strong>ros [options] use</strong> args...</p>
+<p><strong>ros [options] use</strong> impl[/version]</p>
+<p>impl : The name of an implementation which is already installed. New implementations can be downloaded by <em>ros-install</em>(1). The list of installed implementations is available in <em>ros-list</em>(1).</p>
+<p>version: : The version specifier. The string representation of the version (e.g. <major>.<minor>) depends on each implementation and roswell generally follows the representation used by the implementation.</p>
 <!-- # subcommands -->
 
 
@@ -30,6 +32,7 @@
 
 
 <h1>description</h1>
+<p><code>ros use</code> sets the default implementation used by roswell. It is by default <code>sbcl-bin</code>, which is a stable and well-tested version of sbcl.</p>
 <!-- # options -->
 
 <!--  -->
@@ -38,6 +41,6 @@
 
 
 <h1>SEE ALSO</h1>
-<p><em>ros</em>(1)</p>
+<p><em>sbcl</em>(1), <em>ros</em>(1), <em>ros-install</em>(1), <em>ros-list</em>(1)</p>
 </body>
 </html>
diff --git a/documents/ros-use.md b/documents/ros-use.md
index 8da2671..c6a6073 100644
--- a/documents/ros-use.md
+++ b/documents/ros-use.md
@@ -1,8 +1,18 @@
 
-ros-use - 
+ros-use - sets the default implementation used by roswell
 # synopsis
 
-**ros [options] use** args...
+**ros [options] use** impl[/version]
+
+impl
+    : The name of an implementation which is already installed. New
+    implementations can be downloaded by _ros-install_(1).
+    The list of installed implementations is available in _ros-list_(1).
+
+version:
+    : The version specifier. The string representation of the version
+    (e.g. <major>.<minor>) depends on each implementation and roswell
+    generally follows the representation used by the implementation.
 
 <!-- # subcommands -->
 
@@ -12,9 +22,12 @@ ros-use -
 
 # description
 
+`ros use` sets the default implementation used by roswell. It is by default
+`sbcl-bin`, which is a stable and well-tested version of sbcl.
+
 <!-- # options -->
 <!--  -->
 <!-- # Environmental Variables -->
 
 # SEE ALSO
-_ros_(1)
+_sbcl_(1), _ros_(1), _ros-install_(1), _ros-list_(1)