+<foil>
+<title>Allocating numbers</title>
+<para>
+Use <emphasis>register\_chrdev\_region</emphasis> or
+<emphasis>alloc\_chrdev\_region</emphasis> to register or allocate device
+numbers.
+</para>
+<para>
+Use <emphasis>unregister\_chrdev\_region</emphasis> to unregister it.
+</para>
+</foil>
+
+<foil>
+<title>cdev structure</title>
+<para>
+Use <emphasis>cdev\_alloc</emphasis> or <emphasis>cdev\_init</emphasis> to
+allocate or initalize a cdev structure.
+</para>
+<para>
+Use <emphasis>cdev\_add</emphasis> and <emphasis>cdev\_del</emphasis> to
+register and unregister it.
+</para>
+</foil>
+
+<foil>
+<title>Open/Release</title>
+<para>
+Implementing open and release should be very simple for many devices. They
+usually allocate data, and multiplex devices by minor number.
+</para>
+</foil>
+