Check for UL or CE marks and make sure everything follows local codes. Look for damage and test with a multimeter if you know how. Tip: Always wear insulated gloves and safety glasses. If you're unsure, ask an. Whether you are sending or receiving packages, you must have noticed the various packaging symbols on the boxes. Read now and you will know 32 symbols! As a universal language, international packaging symbols are crucial because they offer a means of understanding a package's contents for all. When you receive a shipment, the first thing you usually see isn't the product – it's the packaging. The International Organization sets these symbols for Standardization (ISO), which keeps the data of all these symbols and defines their meaning. They form a globally standardized identification system for quickly communicating handling, storage, shipping, and compliance information. Good labeling of breakers is very important.