Register class is a special class for handling multi page groups. Using this class, you only have to supply an array of groups, describing the register's children. How these children are visualized, either with a cycle gadget of with a register-like group, is the choice of the user. You need to use the Group.Title attribute to give your register tabs titles.
Here is an example of a three page register group:
<register> <vgroup title="Page 1"> <listview> <column> <item>Entry</item> </column> </listview> </vgroup> <vgroup title="Page 2"> <texteditor/> </vgroup> <vgroup title="Page 3"> <button>Click me</button> </vgroup> </register>