WordPress at a glance
filter is not described

clean_url filter-hook . WP 2.3.0

Filters a string cleaned and escaped for output as a URL.

Usage

add_filter( 'clean_url', 'filter_function_name_3914', 10, 3 );
function filter_function_name_3914( $good_protocol_url, $original_url, $_context ){
	// filter...

	return $good_protocol_url;
}
$good_protocol_url(string)
The cleaned URL to be returned.
$original_url(string)
The URL prior to cleaning.
$_context(string)
If 'display', replace ampersands and single quotes only.

Where the hook is called

esc_url()
wp-includes/formatting.php 3880
return apply_filters( 'clean_url', $good_protocol_url, $original_url, $_context );

Where the hook is used (in WP core)

Does not used.