Is it necessary for all products to have a “MADE IN CHINA” or “MADE IN PRC” mark?
For imported goods into The United States, yes it is required. U.S. Customs and Border Protection rules state:
“Prior to importing your goods into the United States, you should ensure the overseas supplier has marked the goods with the country of origin. For example, goods originating in China should be marked "Made in China". The marking must be legible and permanent enough for the ultimate purchaser to be made aware of the goods origin.”