CCNA, CCNP, MCSA, CCNA Final Exam, All Answer Test Module With 100/100

I'm developing a website, but stuck at some point, where i needed to detect outgoing links on my website, and either forbid the links, or accept that, i don't know how facebook is doing this, but they can do it through facebook.com/l.php that if the link is marked spam, users will get notified about it. I don't know if that's a php or htaccess, it worked in php using the DOMDOCUMENT, but it's not a real solution for this.