Ampersands (&"2;s) in URLs

Another common error occurs when including a URL which contains an ampersand ("&"):

...

This example generates an error for "unknown entity section" because the "&" is assumed to begin an entity. In many cases, browsers will recover safely from the error, but the example used here will cause the link to fail in Netscape 3.x (but not other versions of Netscape) since it will assume that the author intended to write §ion, which is equivalent to §ion.

To avoid problems with both validators and browsers, always use & in place of & when writing URLs in HTML:

&section=2">...

Note that replacing & with & is only done when writing the URL in HTML, where "&" is a special character (along with "<" and ">"). When writing the same URL in a plain text email message or in the location bar of your browser, you would use "&" and not "&". With HTML, the browser translates "& a m p ;" to "&" so the Web server would only see "&" and not "& a m p ;" in the query string of the request.