XSS defense. Strict referer checking can make reflective XSS attacks harder, because other sites can't trick the victim's browser into visiting the vulnerable URL.
I did not get it. So if on my site I implemented the referrer checker and it redirects me to a specific page if I am coming from anything else outside of my site, how does it helps me with XSS attacks.
May be I misunderstood something, and also sorry if it is obvious for someone.