Which type of mark would indicate compliance with international standards on a container?

ISO markings are the correct answer because they signify that a shipping container meets the standards set by the International Organization for Standardization (ISO). These standards are essential for ensuring safety, efficiency, and compatibility in international shipping. ISO markings include information such as the container's dimensions, type, and payload capacity, which are crucial for operators and regulatory authorities to ensure that the container is fit for transport according to established global standards.

In contrast, weight labels indicate the maximum weight that a container can safely carry, but they do not inherently signify compliance with international standards. Origin markings provide information about where the container was manufactured but do not necessarily relate to compliance with international shipping regulations. Customs clearance stamps indicate that a container has passed through customs and is cleared for transport, but they also do not express conformity with ISO standards. Therefore, while all the other options have their importance in shipping logistics, ISO markings specifically denote adherence to international requirements.