None.  See documentation.

Versions of perl-ldap below v0.26 do not work with this version
of IO::Socket::SSL because they contain a workaround for old
versions of IO::Socket::SSL that breaks new versions.

---------------------

Note that when writing a preforking server (a server that accepts a
connection and then hands it off to a child for processing), it is
best to handle SSL negotiation after the socket has been passed to
the child (using socket_to_SSL()).  If implemented so that the server
handles negotiation, a failed negotiation may tie up the server until
the connection times out.

---------------------

One user mentioned that the following did not work as it should in
IO::Socket::SSL, but worked in IO::Socket::INET:

chomp($var = <$socket>);
print ord(chop($var));    # Prints "10" for people using ASCII

This is due to a bug in Perl that will be fixed in 5.8.1.  If you need
a workaround, try one of the following:

chomp($var = $socket->getline());
chomp($var = scalar <$socket>);
chomp($var = $var = <$socket>);

Any function that returns the value of <$socket> (in scalar context)
unchanged will work.

-- 
Peter Behroozi (behroozi at www.pls.uni.edu)