Because these are private, these are considered safe to use on currently subscribed cards. A type of card programming hardware. It is where the card interfaces with the computer and software. This is the actual 'program' that is used on a card. They cannot be run directly off of windows, they are run inside a card programming software, such as winexplorer not all scripts are for creating test cards, however.
Some scripts are utilities that make things easier for the tester.
Instead of replacing the actual written cam id on the card as cloning does, the spoofing method, Instead gives the ird a different cam id when it is asked for. Theoretically, This would be the safest of all scripts, but in reality this is not always the case. It refers to the eeprom image, specifically the cam id and zkt. Do not use unless you know what you are doing, or someone who knows what their doing, told you to. A powerful card scripting software.