You can create your own message type by following the code example:
function ts_post_type_test() { register_post_type( 'Test', array( 'label' => __('Test'), 'public' => true, 'show_ui' => true, 'show_in_nav_menus' => false, 'menu_position' => 5, 'capability_type' => 'post', 'texonomies' => array('category'), 'supports' => array( 'title','editor','thumbnail'), ) ); }
wordpress site link: http://codex.wordpress.org/Function_Reference/register_post_type
Use the following link to create a separate category for a specific mail use:
http://codex.wordpress.org/Function_Reference/register_taxonomy
Code example:
register_taxonomy('name of taxonomy', 'post name',array("hierarchical" => true,"label" => "Label Category","singular_label" => "label of taxonomy",'update_count_callback' => '_update_post_term_count','query_var' => true,'rewrite' => array( 'slug' => 'slug name of new registered taxonomy', 'with_front' => false ),'public' => true,'show_ui' => true,'show_tagcloud' => true,'_builtin' => false,'show_in_nav_menus' => false));
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