WordPress at a glance
filter is not described

plugins_url filter-hook . WP 2.8.0

Filters the URL to the plugins directory.

Usage

add_filter( 'plugins_url', 'filter_function_name_5538', 10, 3 );
function filter_function_name_5538( $url, $path, $plugin ){
	// filter...

	return $url;
}
$url(string)
The complete URL to the plugins directory including scheme and path.
$path(string)
Path relative to the URL to the plugins directory. Blank string if no path is specified.
$plugin(string)
The plugin file path to be relative to. Blank string if no plugin is specified.

Where the hook is called

plugins_url()
wp-includes/link-template.php 3185
return apply_filters( 'plugins_url', $url, $path, $plugin );

Where the hook is used (in WP core)

Does not used.