unregister_sidebar()
Function: Removes a sidebar from the list.
Source: wp-includes/widgets.php:331
is_registered_sidebar()
Function: Checks if a sidebar is registered.
Source: wp-includes/widgets.php:347
wp_register_sidebar_widget()
Function: Register an instance of a widget.
Source: wp-includes/widgets.php:386
wp_register_sidebar_widget
Action Hook: Fires once for each registered widget.
Source: wp-includes/widgets.php:422