This is nothing new, it is simply script code that is usually used for different things, among other methods of SQL injection and also bypass of certain forums such as 4chan.
But those are already other areas that I will not comment on.
This is usually used for when I need to see if I am writing the password of a site correctly, because it is necessary to see if the symbol or letter has been written correctly without having to resort to copy and paste
you are right it is not new but I find it quite useful, there are many tools like this that seem simple but are still useful, an example is that a couple of days ago a friend showed me what you can do with one of the first portable firefox, they are using it to bypass the security of a platform ami never would have occurred to me that something so old serve today in that way, thanks for your comment