This recommended practice describes a system for identifying transfer points and equipment for loading and unloading of petroleum fuels and related products with colors and symbols. The Color-Symbol system described in this recommended practice does not cover aviation fuels. Color-Symbol systems for aviation fuels are described in IP-1542.
![API RP 1637:2020](https://www.365standards.com/wp-content/uploads/2023/02/API-RP-1637-2020.png)