[The Alchemist]

Thanks for making such a nice tutorial on this. But, since I'm not very good at WAF bypassing, I'm having a confusion.
I didn't understand one thing, /**/ are supposed to be comment tags right?
So, as you said, we could use this in the URL :

Code:

id=1/*!UnIoN*/SeLeCT

The term UnIoN is within the comment tags. And whatever is within the comment tags doesn't get executed right? So, I'm confused about how this is supposed to get executed.