seo规范
Avoid duplicate content. Every good Search Engine Optimization expert will tell you that original content is the best way to succeed in your attempt to climb the slippery search engine slope. Copying content from elsewhere or syndicating the the same content to other sites can have an adverse effect your page rank.
避免重复内容。 每位优秀的搜索引擎优化专家都会告诉您，原始内容是成功攀登湿滑的搜索引擎坡度的最佳途径。 从其他地方复制内容或将相同内容联合发布到其他站点可能会对您的网页排名产生不利影响。
Unfortunately, most websites inadvertently publish duplicate text. Consider your home page; is the same content available from different URLs?…
不幸的是，大多数网站无意间发布了重复的文本。 考虑您的主页； 可以从不同的URL获得相同的内容吗？…
http://www.mysite.com/ http://www.mysite.com/index.html http://www.mysite.com/index.php?sessionid=57
http://www.mysite.com/ http://www.mysite.com/index.html http://www.mysite.com/index.php?sessionid=57
Few content management systems handle duplicate pages well. A URL rewrite engine, such as Apache’s mod_rewrite, can help but it is difficult to guarantee a unique addresses for every page. Google and the other search engines do their best to address non-malicious duplication, but you can never be certain that your website has not been downgraded.
很少有内容管理系统能够很好地处理重复页面。 URL重写引擎 (例如Apache的mod_rewrite )可以提供帮助，但是很难保证每个页面的唯一地址。 Google和其他搜索引擎会尽最大努力解决非恶意复制，但是您永远不能确定自己的网站尚未降级。
The duplicate content problem has finally been resolved with Google’s new canonical element. Web developers can indicate their preferred page URL using a new <link> tag in the HTML <head>. For example:
重复的内容问题终于通过Google的新规范元素得以解决。 Web开发人员可以使用HTML <head>中的新<link>标记来指示其首选页面URL。 例如：
<link rel="canonical" href="http://www.mysite.com/" />
<link rel="canonical" href="http://www.mysite.com/" />
Note:
注意：
The canonical URL must be on the same domain, although sub-domains such as www.mysite.com and products.mysite.com are permitted.
规范URL必须在同一域中，尽管允许使用子域，例如www .mysite.com和product .mysite.com。
Relative path names are handled and Google will resolve URLs to any path set by the page’s
<base>link.处理相对路径名，Google会将URL解析为页面
<base>链接设置的任何路径。- The preferred URL does not need to contain an exact replica of the original page content. Google will permit slight differences, such as the order of a list of products. However, it is certainly advisable to avoid that situation where possible. 首选URL不需要包含原始页面内容的精确副本。 Google将允许有细微的差异，例如产品列表的顺序。 但是，最好避免这种情况。
- Google will follow canonical chains, but recommend that a single valid URL is specified for the best results. Google会遵循规范的链条，但建议您指定一个有效的URL以获得最佳效果。
Further information and instructions are available at the Google Webmaster Central Blog. The tag is being parsed by the GoogleBot now. Both Microsoft and Yahoo have agreed to the proposal; they are likely to follow shortly.
有关更多信息和说明，请访问Google网站站长中央博客 。 GoogleBot现在正在解析该标签。 微软和雅虎都同意了这一提议。 他们很可能会很快跟进。
Have you experienced page rank problems owing to duplicate content within your site? Will the canonical element assist with your SEO effort?
您是否因网站中的内容重复而遇到网页排名问题？ 规范元素会协助您进行SEO吗？
翻译自: https://www.sitepoint.com/improve-seo-google-canonical-element/
seo规范
