Customized roles

The example in the FAQ is fairly incomplete.

You could add the following to the functions.php of your (child) theme:

add_filter( 'if_menu_conditions', 'my_new_menu_conditions' );
function my_new_menu_conditions( $conditions ) {
    $conditions[] = array(
        'name'      =>  'If single custom-post-type',   // name of the condition
        'condition' =>  function() {                    // callback - must return TRUE or FALSE
            return is_singular( 'my-custom-post-type' );
        }
    );

	return $conditions;
}

Note about the “return $conditions;”. That one is missing in the example but is very important!