RSS feed question

Do I really need all those xmlns links in my RSS code?

what does the following code mean?

<rss version="2.0"
xmlns:content="http://purl.org/rss/开发者_运维知识库1.0/modules/content/"
xmlns:wfw="http://wellformedweb.org/CommentAPI/"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:atom="http://www.w3.org/2005/Atom"
xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
>

The xmlns properties define XML namespaces.

For instance, xmlns:atom="http://www.w3.org/2005/Atom" defines the namespace atom to be the URI http://www.w3.org/2005/Atom.

Then, when you create a <atom:link> element, you can see it as having the URI http://www.w3.org/2005/Atom/link, which the parser will know is a link, as defined in the Atom specification.

Note, the parser cannot go by the name of the namespace, as you just as easily could have used xmlns:a="http://www.w3.org/2005/Atom", which would make <a:link> the Atom link tag.