WordPress at a glance
filter is not described

sanitize_textarea_field filter-hook . WP 4.7.0

Filters a sanitized textarea field string.

Usage

add_filter( 'sanitize_textarea_field', 'filter_function_name_9111', 10, 2 );
function filter_function_name_9111( $filtered, $str ){
	// filter...

	return $filtered;
}
$filtered(string)
The sanitized string.
$str(string)
The string prior to being sanitized.

Where the hook is called

sanitize_textarea_field()
wp-includes/formatting.php 4736
return apply_filters( 'sanitize_textarea_field', $filtered, $str );

Where the hook is used (in WP core)

Does not used.