I’m a professional web developer, and yet I learned this one from my Mom, which she read in Reader’s Digest Magazine.
In a url, everything to the left of an @ symbol is ignored.
For example, if you copy/past google.com@yahoo.com into your url bar, you’ll be taken to Yahoo, not Google. Not a big deal, just be aware that the second url might be a spammer or con artist trying to make their url look like it’s from a legitimate source.
This seems to be the case in all browsers. However, if the @ symbol appears to the right of the TLD, the domain is interpreted correctly.