diff --git a/docs/source/guides/admin-guides/references/man5/site.5.rst b/docs/source/guides/admin-guides/references/man5/site.5.rst
index 33f4ac5e3..6700c946c 100644
--- a/docs/source/guides/admin-guides/references/man5/site.5.rst
+++ b/docs/source/guides/admin-guides/references/man5/site.5.rst
@@ -465,7 +465,11 @@ site Attributes:
   
    xcatlport:  The port used by xcatd command log writer process to collect command output.
   
-   xcatsslversion:  The ssl version by xcatd. Default is TLSv1.
+   xcatsslversion:  The SSL_version option xcatd used and passed to
+                    IO::Socket::SSL->start_SSL(). By default, this value is
+                    set to empty. In this case, xcatd will use
+                    'SSLv23:!SSLv2:!SSLv3:!TLSv1' internally.
+                    For more detail, see https://metacpan.org/pod/IO::Socket::SSL
   
    xcatsslciphers:  The ssl cipher by xcatd. Default is 3DES.