You often see those symbols on plastics. Sadly, it is easy to misinterpret them. It happened to me the other day when I bought the eiPott egg cups. Buying dishwasher safe tableware is a must for me. Therefore, I am a little bit disappointed of my purchase.
People often confuse the cup and fork symbol for the dishwasher safe symbol. The thing is that there is not universally approved symbol for dishwasher safe. The cup and fork means that the material is safe for food use.
It is strange that this area of the food industry has no standards. The use of symbol on products eliminate the need for language translation. Sometimes, the instructions are written on the packaging but not on the item. Do the brands expect us to recall the product care for every item we purchased. In fact, I only bought dishwasher safe tableware to not have to remember which one is safe, which one is not.
I hope this will help you make good purchase decisions.