WordPress at a glance
action is not described

restore_previous_locale action-hook . WP 4.7.0

Fires when the locale is restored to the previous one.

Usage

add_action( 'restore_previous_locale', 'action_function_name_4314', 10, 2 );
function action_function_name_4314( $locale, $previous_locale ){
	// action...
}
$locale(string)
The new locale.
$previous_locale(string)
The previous locale.

Where the hook is called

WP_Locale_Switcher::restore_previous_locale()
restore_previous_locale
wp-includes/class-wp-locale-switcher.php 127
do_action( 'restore_previous_locale', $locale, $previous_locale );

Where the hook is used (in WP core)

Does not used.