specifying networks is <replaceable
     class="parameter">address/y</replaceable> where <replaceable
     class="parameter">address</replaceable> is the network's lowest
     address represented as an
     IPv4 or IPv6 address, and <replaceable
     class="parameter">y</replaceable> is the number of bits in the netmask.  If
     <replaceable class="parameter">y</replaceable> is omitted, it is calculated
     using assumptions from the older classful network numbering system, except
     it will be at least large enough to include all of the octets
     written in the input.  It is an error to specify a network address
     that has bits set to the right of the specified netmask.
    </para>

    <para>
     <xref linkend="datatype-net-cidr-table"/> shows some examples.
    </para>

     <table id="datatype-net-cidr-table">
      <title><type>cidr</type> Type Input Examples</title>
      <tgroup cols="3">
       <thead>
        <row>
         <entry><type>cidr</type> Input</entry>
         <entry><type>cidr</type> Output</entry>
         <entry><literal><function>abbrev(<type>cidr</type>)</function></literal></entry>
        </row>
       </thead>
       <tbody>
        <row>
         <entry>192.168.100.128/25</entry>
         <entry>192.168.100.128/25</entry>
         <entry>192.168.100.128/25</entry>
        </row>
        <row>
         <entry>192.168/24</entry>
         <entry>192.168.0.0/24</entry>
         <entry>192.168.0/24</entry>
        </row>
        <row>
         <entry>192.168/25</entry>
         <entry>192.168.0.0/25</entry>
         <entry>192.168.0.0/25</entry>
        </row>
        <row>
         <entry>192.168.1</entry>
         <entry>192.168.1.0/24</entry>
         <entry>192.168.1/24</entry>
        </row>
        <row>
         <entry>192.168</entry>
         <entry>192.168.0.0/24</entry>
         <entry>192.168.0/24</entry>
        </row>
        <row>
         <entry>128.1</entry>
         <entry>128.1.0.0/16</entry>
         <entry>128.1/16</entry>
        </row>
        <row>
         <entry>128</entry>
         <entry>128.0.0.0/16</entry>
         <entry>128.0/16</entry>
        </row>
        <row>
         <entry>128.1.2</entry>
         <entry>128.1.2.0/24</entry>
         <entry>128.1.2/24</entry>
        </row>
        <row>
         <entry>10.1.2</entry>
         <entry>10.1.2.0/24</entry>
         <entry>10.1.2/24</entry>
        </row>
        <row>
         <entry>10.1</entry>
         <entry>10.1.0.0/16</entry>
         <entry>10.1/16</entry>
        </row>
        <row>
         <entry>10</entry>
         <entry>10.0.0.0/8</entry>
         <entry>10/8</entry>
        </row>
        <row>
         <entry>10.1.2.3/32</entry>
         <entry>10.1.2.3/32</entry>
         <entry>10.1.2.3/32</entry>
        </row>
        <row>
         <entry>2001:4f8:3:ba::/64</entry>
         <entry>2001:4f8:3:ba::/64</entry>
         <entry>2001:4f8:3:ba/64</entry>
        </row>
        <row>
         <entry>2001:4f8:3:ba:&zwsp;2e0:81ff:fe22:d1f1/128</entry>
         <entry>2001:4f8:3:ba:&zwsp;2e0:81ff:fe22:d1f1/128</entry>
         <entry>2001:4f8:3:ba:&zwsp;2e0:81ff:fe22:d1f1/128</entry>
        </row>
        <row>
         <entry>::ffff:1.2.3.0/120</entry>
         <entry>::ffff:1.2.3.0/120</entry>
         <entry>::ffff:1.2.3/120</entry>
        </row>
        <row>
         <entry>::ffff:1.2.3.0/128</entry>
         <entry>::ffff:1.2.3.0/128</entry>
         <entry>::ffff:1.2.3.0/128</entry>
        </row>
       </tbody>
      </tgroup>
     </table>
   </sect2>

   <sect2 id="datatype-inet-vs-cidr">
    <title><type>inet</type> vs. <type>cidr</type></title>

    <para>
    The essential difference between <type>inet</type> and <type>cidr</type>
    data types is that <type>inet</type> accepts values with nonzero bits to
    the right of the netmask, whereas <type>cidr</type> does not.  For
    example, <literal>192.168.0.1/24</literal> is valid for <type>inet</type>
    but not for <type>cidr</type>.