SWAU - street autographs?

Hi, I recently purchased an autograph from a business (reputable) who said the autograph was ‘guaranteed to pass an authentication check but not SWAU since they don’t authenticate street graphs’. I’ve looked it up online and there’s no information about this so does anyone on this page know by any chance? You’d really be helping me out as there’s been a fair few issues with this company and I want to know if I’ve been scammed. Thanks in advance :)