Implement the @ Virtual domain Name System in the Web (principle)

Found this very good dongdong oh, dedication to everyone. We do not have to pay to register the domain name, hehe!
Many netizens may find that there are virtual domain names in some websites, especially personal websites, that use youname@xxx.com. When I told my friends, they all said it wasn't an e-mail address? Actually it is, but if you enter it into the browser's address, it is not, but literally a child domain name. If you don't believe it, you type http://bbs@luyu.net and http://guestbook@luyu.net in the browser. is not found that they are two different addresses, the former is the site BBS login page, the latter is the website, and this site is the home page is http://luyu.net, very cool bar.
Some netizens also asked why not http://bbs.luyu.net and http://guestbook.luyu.net do virtual domain name, this is the real two-level subdomain. Because it's no different in terms of implementation, just ". "In the domain name role can be very different, you can use http://www.luyu.net access, it is not http://www@luyu@net it, because". "To take into account an analytic decoding problem." So to do. " "The virtual domain name must enable the domain Name service provider to open the role of the pan-domain name, is as long as in the browser's address bar type *.luyu.net domain name, will first go to the Luyu.net server to request resolution decoding service, so that, to achieve unlimited number of free". "The virtual domain name is not difficult." Most of the key universal domain name Open is to receive 100 to 200 yuan, so we do not consider the use of free @ domain name. Some netizens also ask why not to "!#$%" other symbols and must use @ it, this point in reading the following article you will naturally understand.
Through this article you can make your own @ domain name. Then I will be the administrator, want to add any links can, including Chinese, think directly to play http://wallpaper @luyu.net that much fun ah. But the Chinese should pay attention to is the UTF-8 standard question.
Let's start with the realization of all aspects of the @ virtual domain name.
@ The implementation of the virtual domain name begins with the method of logging on to the FTP server directly in the browser as a user and password. For example: In the browser's address bar type password:username@ftp://my.ftp.com, at this time IE will automatically user "username" and password "password" landing FTP server; the equivalent of typing FTP in the browser's address bar first ://my.ftp.com, enter the login page, and then enter the username and password at the prompt. What is this for? Originally in the http1.1 protocol, it is required to implement the HTTP access authorization function, in the form of the above password:username@ftp or the server host sent by header. Then one of the password can be omitted, that is, access to the username@ server host, is tantamount to username access to this server host, just like I think we will understand why we can use @, and not other symbols. So said Guestbook@luyu.net, in fact, is to guestbook users to access the Luyu.net host, but why can access to the page of the guest book? In fact, this is just a simple page jump function, the specific in the following will be discussed.