WordPress at a glance
filter is not described

woocommerce_coupon_code_generator_characters filter-hook . WC 1.0

Usage

add_filter( 'woocommerce_coupon_code_generator_characters', 'filter_function_name_1175' );
function filter_function_name_1175( $string ){
	// filter...

	return $string;
}
$string
-

Where the hook is called

WC_Admin_Assets::admin_scripts()
woocommerce_coupon_code_generator_characters
woocommerce/includes/admin/class-wc-admin-assets.php 294
'characters'           => apply_filters( 'woocommerce_coupon_code_generator_characters', 'ABCDEFGHJKMNPQRSTUVWXYZ23456789' ),

Where in WP core the hook is used WooCommerce

Usage not found.