google对网站进行索引时，会有两种索引，一个是主索引，一个是补充索引。补充索引存储着搜索引擎认为不太重要的内容。

2009-06-10 12:09:02

Google已经从搜索结果页中删除了"补充结果"标签 。 "补充结果"曾经可让用户在主索引以外的地方针对查询查找结果。 然而，由于这些网址是"补充性"的， 因此不会像Google主索引中的网址那样经常得到抓取和更新 。

随着时间的推移，Google改进了技术，现在Google已经可以更频繁地抓取网站并编制索引。 现在Google的整个网络索引能更快地反映最新情况，"补充结果"标签也就逐渐失去了其作用。

对于使用补充结果标签做为诊断辅助手段的网站管理员，Google建议使用Google的网站管理员工具和 Analytics（分析）服务。 这些免费的服务可让你深入了解用户和 Google 认为不太相关的网页。

以上内容来自google的“ 网站管理员/站长帮助”，可以看出补允索引(Supplemental Result)已经没有什么意义，所以seo时也就不用再考虑补允索引(Supplemental Result)这个东西了！

Supplemental resultsPrint
We've removed the label "Supplemental Result" from our search result pages. Supplemental Results once enabled users to find results for queries beyond our main index. Because they were "supplemental," however, these URLs were not crawled and updated as frequently as URLs in our main index.

Google's technology has improved over time, and now we're able to crawl and index sites with greater frequency. With our entire web index fresher and more up to date, the "Supplemental Results" label outlived its usefulness.

For webmasters who have used the supplemental result label as a diagnostic aid, Google encourages the use of our Webmaster Tools and also our Analytics service. These free services can provide you with insight into those pages that users and Google may find less relevant.