WordPress at a glance
filter is not described

print_styles_array filter-hook . WP 2.6.0

Filters the array of enqueued styles before processing for output.

Usage

add_filter( 'print_styles_array', 'filter_function_name_7000' );
function filter_function_name_7000( $to_do ){
	// filter...

	return $to_do;
}
$to_do(array)
The list of enqueued styles about to be processed.

Where the hook is called

WP_Styles::all_deps()
print_styles_array
wp-includes/class.wp-styles.php 307
$this->to_do = apply_filters( 'print_styles_array', $this->to_do );

Where the hook is used (in WP core)

Does not used.