Callback is a function which will be called after determining the value. The value will be passed to the function as a number. Below you can see a status match table:
status = -1 // time out
status = 0 // good
status = 1 // warning
status = 2 // alert
For example, if a user is determined by ADEX as alert, using callback, you can block all the content on the page for such user, etc.
Below you can see an example of the easiest callback, which outputs the status in console: