There are no noticeable stains. The serial number is listed on the inside of the package. I purchased and used the genuine version, but I am selling it because I am disposing of my old Mac. Adobe support has expired. User registration is also not possible. I have uninstalled and deleted it from my Mac. Since I cannot guarantee its operation, I am selling it as a junk item. Please purchase only if you have the necessary knowledge. However, since it comes with a serial number, please understand that no claims or returns will be accepted.