Excuse me, do you want to add a few words after English abbreviation Co., Ltd. What is right and why? thank you

Co, the abbreviation of company; Ltd has limited representatives; Limited companies together are limited companies, which means limited companies. "."and "Co" are symbols for word abbreviations in English, so there should also be a "."after "Ltd" (some companies also have one in English). "After" Limited Company "). The ","after "co." is a separator to distinguish the two words.