one of the documented procedures in this installation of the ACS
ec_product_name   product_id   { value_if_not_found "" }
What it does:
Returns product name from product_id, memoized for efficiency
Defined in: /web/philip/tcl/ecommerce-defs.tcl

Source code:

    # throw an error if this isn't an integer (don't want security risk of user-entered
    # data being eval'd)
    validate_integer "product_id" $product_id
    set tentative_name [util_memoize "ec_product_name_internal $product_id" 3600]
    if [empty_string_p $tentative_name] {
	return $value_if_not_found
    } else {
	return $tentative_name