wp-includes/ms-deprecated.php:320Adds an 'updated=true' argument to a URL.
$urlstringoptional''stringfunction wpmu_admin_redirect_add_updated_param( $url = '' ) { _deprecated_function( __FUNCTION__, '3.3.0', 'add_query_arg()' ); if ( ! str_contains( $url, 'updated=true' ) ) { if ( ! str_contains( $url, '?' ) ) return $url . '?updated=true'; else return $url . '&updated=true'; } return $url;}Introduced in MU (3.0.0). Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/ms-deprecated.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.