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filter is not described

query_string filter-hook . WP 1.5.0

Deprecated in 2.1.0. It is no longer supported and can be removed in future releases. Use query_vars' or 'request' filters instead.

Deprecated: 2.1.0 Use 'query_vars' or 'request' filters instead.

Filters the query string before parsing.

Usage

add_filter( 'query_string', 'filter_function_name_6009' );
function filter_function_name_6009( $query_string ){
	// filter...

	return $query_string;
}
$query_string(string)
The query string to modify.

Where the hook is called

WP::build_query_string()
wp-includes/class-wp.php 537
$this->query_string = apply_filters( 'query_string', $this->query_string );

Where the hook is used (in WP core)

Does not used.