WordPress at a glance
filter is not described

update_footer filter-hook . WP 2.3.0

Filters the version/update text displayed in the admin footer.

WordPress prints the current version and update information, using core_update_footer() at priority 10.

Usage

add_filter( 'update_footer', 'filter_function_name_1378' );
function filter_function_name_1378( $content ){
	// filter...

	return $content;
}
$content(string)
The content that will be printed.

Where the hook is called

In file: /wp-admin/admin-footer.php
update_footer
wp-admin/admin-footer.php 59
echo apply_filters( 'update_footer', '' );

Where the hook is used (in WP core)

wp-admin/includes/admin-filters.php 128
add_filter( 'update_footer', 'core_update_footer' );