The following is an overview of the most common codes: Use the below to calculate size/type of a less commonly used ISO 6346 containers: Country code (optional) The country code consists of two capital letters of the Latin alphabet as described in ISO 3166-1. It indicates the country where the code is registered not the nationality of the owner or operator of the container. The letters of the code shall not be less than high. Mandatory operational marks Operational marks are intended solely to convey information requested for the movement of containers or give visual warnings. They relate to the weight of containers a symbol to denote air-surface container a sign warning of overhead electrical danger height marks for containers higher than See also Standard Carrier Alpha Code UIC wagon numbers The following is a list of further freight container related ISO specifications, where not all have an article assigned yet (you can help improve Wikipedia and start one): ISO 668 - Freight containers - Classification, dimensions and ratings ISO 830 - Freight containers - Terminology ISO 1161 - Freight containers - Corner fittings - Specification ISO 1496 - Freight containers - Specification and testing ISO 2308 - Hooks for lifting freight containers of up to 30 tons capacity - Basic requirements ISO 3874 - Freight containers - Handling and securing ISO 8323 - Freight containers - Air/surface (intermodal) general purpose containers - Specification and tests ISO 9669 - Freight containers - Interface connections for tank containers ISO 9711 - Freight containers - Information related to containers on board vessels ISO 9897 - Container equipment data exchange (CEDEX) ISO 10368 - Freight thermal containers - Remote condition monitoring ISO 10374 - Freight containers - Automatic identification References Notes Sources Bureau International des Containers Container Numbering Guide External links Bureau International des Containers (BIC) BIC Check Digit Calculator BIC Code Identifier Freight Container Check Digit Calculator (includes Java source code for download *Static Java Method does not convert "10" check digit to "0") List of owner codes (not the official BIC site) Online check digit calculator Container numbers validator Cargo container validator ISO 6346 in Javascript Command line application to generate or validate container numbers. 06346 Intermodal containers Port infrastructure Checksum algorithms Encodings