A more thorough explanation:

Definition: Patent marking refers to the act of incorporating or affixing a patent number to a patented article's surface or surrounding packaging. This is done to give constructive notice of patent rights to infringers. Without the number in place, a patentee cannot recover losses that occur before the infringer has actual notice of the patent.

Example: Let's say a company has patented a new type of phone case. To protect their patent rights, they must affix the patent number to the phone case or its packaging. This way, if someone else tries to make or sell a similar phone case without permission, they will be considered an infringer and the patentee can take legal action to recover any losses.

Explanation: Patent marking is an important step in protecting a patentee's rights. By affixing the patent number to a product, the patentee is giving notice to potential infringers that the product is protected by a patent. This means that if someone else tries to make or sell a similar product without permission, they will be considered an infringer and can be held liable for any damages. Without patent marking, the patentee may not be able to recover losses that occur before the infringer has actual notice of the patent.