Tayfun Coskun | Anadolu Agency | Getty Images Visa, the world’s largest payment processor, said Saturday it will implement a new merchant class code for U.S. gun retailers that will identify transactions at firearms stores. The International Organization for Standardization (ISO) approved the creation of the trade code on Friday after pressure from gun control activists who say it will help track suspicious gun purchases. “Following ISO’s decision to establish a new merchant class code, Visa will take the next steps while ensuring that we protect all legitimate commerce on the Visa network in accordance with our long-standing rules,” Visa said in a statement. Mastercard said on Friday that following ISO approval, “we are now turning our focus to how it will be implemented by merchants and their banks as we continue to support legitimate purchases on our network while protecting privacy and decisions of individual cardholders”. American Express said that when ISO develops a new code, the company will work with third-party processors and partners to implement. The code will show where a person spends money but not what items were purchased. Several top US pension funds, including those for state employees in New York and California, had filed shareholder resolutions asking the payers to weigh in on the issue. Some gun rights activists have worried that the new code could lead to unauthorized surveillance. Mass shootings this year, including one at a Texas elementary school that killed 19 children and two teachers, have added to the long-running debate in the US over gun control. US President Joe Biden has asked Congress to approve an assault weapons ban as well as $37 billion for crime prevention programs, with $13 billion to hire and train an additional 100,000 police officers over the next five years.