「nofollow」再進化：辨識連結性質的新方法
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2019 年 9 月 10 日，星期二
為了抵禦垃圾留言，Google 大約在 15 年前推出了 nofollow 屬性。不久後，這項屬性也成為了 Google 建議用來標記廣告相關連結和贊助商連結的其中一種方法。隨著網路不斷發展，現在是時候讓這項在 2005 年推出的屬性有所進化了。
我們現在將發布兩個新的連結屬性，讓網站管理員能夠利用更多方式對 Google 搜尋指出特定連結的性質。以下是這些屬性和 nofollow 的大致介紹：
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rel="sponsored"：sponsored 屬性的作用是指出網站上做為廣告、贊助或其他報酬協議的一部分所建立的連結。
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rel="ugc"：UGC 代表使用者自製內容；我們建議針對使用者自製內容 (例如留言和論壇文章) 中的連結使用 ugc 屬性值。
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rel="nofollow"：如果您想連結到某個網頁，但是不想提供任何類型的背書 (包括將排名功勞傳遞至其他網頁)，請使用這項屬性。
在 nofollow 推出後，Google 的搜尋演算法就不會考慮加上這個標記的任何連結，但如今情況已有改變。現在 Google 會將所有連結屬性 (sponsored、ugc 和 nofollow) 當成提示，據此判斷應該在搜尋結果中包含或排除哪些連結，往後也會運用這些提示和其他信號，進一步瞭解要如何讓我們的系統妥善分析及使用連結。
我們之所以不和先前對待含有 nofollow 屬性的連結一樣完全忽略這類連結，是因為我們可以運用從連結中獲得的寶貴資訊改進搜尋服務，比如，我們可以從連結中的文字瞭解連結指向的內容。透過觀察我們遇到的每個連結，我們也能更好地理解非自然連結模式。藉由將連結屬性當成提示，我們就不會再錯過這些重要資訊，同時網站擁有者還是能表明不想對哪些連結提供背書。
我們知道大家會對這些新屬性有所疑問，希望下方的常見問題集可以解答大部分疑問。
我需要變更現有的 nofollow 連結嗎？
不需要。如果您現在是用 nofollow 封鎖贊助商連結，或表明您無法保證所連結網頁的品質，我們仍支援這些做法，您完全不必變更現有的 nofollow 連結。
是否能在一個連結中使用多個 rel 值？
是的，您可以在一個連結中使用多個 rel 值。舉例來說，rel="ugc sponsored" 就是一個完全有效的屬性，代表連結本身是贊助商連結，來源為使用者自製內容。此外，如果想回溯相容於不支援新屬性的服務，也可以將 nofollow 與 rel="nofollow ugc" 等新屬性搭配使用。
不需要。您可以繼續將 nofollow 當成標記這類連結的方法，以免因為連結配置問題受到處罰。您完全不必修改現有標記。如果您使用的系統會在新連結中附加這項屬性，則可繼續如此。但如果方便的話，我們仍建議改用 rel="sponsored"。
是的。如果想避免因為連結配置問題而受到處理，請使用 rel="sponsored" 或 rel="nofollow" 來標記這些連結。雖然我們比較偏好 sponsored，但您要使用上述任一屬性皆可，我們對於這兩種屬性的處理方式毫無差別。
如果對連結使用錯誤的屬性，會怎麼樣？
只有贊助商連結可能會出現誤用屬性的情況。如果您使用 sponsored 標記 UGC 連結或非廣告連結，雖然我們會看到這項提示，但影響最多不過是該連結無法計入所連結網頁的排名權重，目前有許多使用 nofollow 標記的 UGC 連結和非廣告連結也都是如此。
不過，反過來情況就不同了。如前文所述，只要連結的性質明確是廣告連結或贊助商連結，就應該使用 sponsored 或 nofollow 屬性。我們建議使用 sponsored，但要使用 nofollow 也沒問題。
為什麼要使用這些新屬性？
新屬性能讓我們更妥善地處理連結，根據連結透露的資訊來分析網頁。如果有人使用這些屬性連結到您的內容，您的內容同樣可能得益於此。
將連結屬性當成「提示」會不會導致留言和 UGC 內容中比較容易出現垃圾連結？
很多開放第三方提供內容的網站都已經在用各種方式阻擋垃圾連結，比如可以整合至許多網誌平台的審查工具，還有人工審查機制。即便如此，ugc 和 nofollow 連結屬性仍有助於進一步防止垃圾連結氾濫。在大多數情況下，改用「提示」不會改變我們處理這類連結的方式。一般來說，我們先前是如何處理標示 nofollow 的連結，往後就會如何處理標示其他屬性的連結，也不會參考這些屬性進行排名。我們會和以往一樣謹慎評估如何在 Google 搜尋中使用連結，在處理未提供屬性的連結時也是如此。
這些屬性和異動會在何時生效？
我們現在就會將所有連結屬性 (sponsored、ugc 和 nofollow) 當成排名的提示，並從 2020 年 3 月 1 日開始將 nofollow 當成檢索及建立索引的提示。如果網站純粹是依賴 nofollow 來禁止搜尋引擎建立網頁索引 (我們從未建議這麼做)，網站管理員則應參閱「瞭解如何禁止 Google 檢索網址」說明頁面，為網站採用更完善的機制。
發文者：Danny Sullivan 和 Gary Illyes
除非另有註明，否則本頁面中的內容是採用創用 CC 姓名標示 4.0 授權，程式碼範例則為阿帕契 2.0 授權。詳情請參閱《Google Developers 網站政策》。Java 是 Oracle 和/或其關聯企業的註冊商標。
[null,null,[],[[["\u003cp\u003eGoogle is introducing two new link attributes, \u003ccode\u003erel="sponsored"\u003c/code\u003e and \u003ccode\u003erel="ugc"\u003c/code\u003e, to provide webmasters with more ways to identify the nature of links for Google Search.\u003c/p\u003e\n"],["\u003cp\u003eAll link attributes (\u003ccode\u003esponsored\u003c/code\u003e, \u003ccode\u003eugc\u003c/code\u003e, and \u003ccode\u003enofollow\u003c/code\u003e) are now treated as hints by Google's search algorithms, rather than directives, for analyzing and using links.\u003c/p\u003e\n"],["\u003cp\u003eExisting \u003ccode\u003enofollow\u003c/code\u003e links do not need to be changed, but using the new attributes is encouraged for better link analysis and processing by Google.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003enofollow\u003c/code\u003e will transition to being treated as a hint for crawling and indexing purposes starting March 1, 2020, meaning it will no longer reliably block pages from being indexed.\u003c/p\u003e\n"],["\u003cp\u003eGoogle recommends using more robust methods described on their help page for blocking URLs from Google, instead of relying on \u003ccode\u003enofollow\u003c/code\u003e for that purpose.\u003c/p\u003e\n"]]],["Google introduced two new link attributes: `rel=\"sponsored\"` for ads or sponsorships and `rel=\"ugc\"` for user-generated content. Alongside the existing `nofollow`, these attributes now serve as \"hints\" for Google Search's algorithms, influencing how links are analyzed. While `nofollow` will be treated as a hint starting March 1, 2020, existing `nofollow` links don't need to be changed. Using `sponsored` or `nofollow` for ads remains crucial to avoid link scheme penalties. These changes aim to enhance link analysis and understanding of web content.\n"],null,["# Evolving \"nofollow\" – new ways to identify the nature of links\n\nTuesday, September 10, 2019\n\n\nNearly 15 years ago, the [`nofollow`\nattribute](/search/docs/advanced/guidelines/qualify-outbound-links) was [introduced](https://googleblog.blogspot.com/2005/01/preventing-comment-spam.html)\nas a means to help fight comment spam. It also quickly became one of Google's\n[recommended methods](/search/docs/essentials/spam-policies#link-spam)\nfor flagging advertising-related or sponsored links. The web has evolved since nofollow was\nintroduced in 2005 and it's time for nofollow to evolve as well.\n\n\nToday, we're announcing two new link attributes that provide webmasters with additional ways\nto identify to Google Search the nature of particular links. These, along with\n`nofollow`, are summarized below:\n\n- **`rel=\"sponsored\"`:** Use the sponsored attribute to identify links on your site that were created as part of advertisements, sponsorships or other compensation agreements.\n- **`rel=\"ugc\"`:** UGC stands for User Generated Content, and the `ugc` attribute value is recommended for links within user generated content, such as comments and forum posts.\n- **`rel=\"nofollow\"`:** Use this attribute for cases where you want to link to a page but don't want to imply any type of endorsement, including passing along ranking credit to another page.\n\n\nWhen nofollow was introduced, Google would not count any link marked this way as a signal to use\nwithin our\n[search algorithms](https://www.google.com/search/howsearchworks/how-search-works/ranking-results/).\nThis has now changed. All the link attributes---`sponsored`, `ugc`, and\n`nofollow`---are treated as hints about which links to consider or exclude within\nSearch. We'll use these hints---along with other signals---as a way to better understand\nhow to appropriately analyze and use links within our systems.\n\n\nWhy not completely ignore such links, as had been the case with `nofollow`? Links\ncontain valuable information that can help us improve search, such as how the words within links\ndescribe content they point at. Looking at all the links we encounter can also help us better\nunderstand unnatural linking patterns. By shifting to a hint model, we no longer lose this\nimportant information, while still allowing site owners to indicate that some links shouldn't be\ngiven the weight of a first-party endorsement.\n\n\nWe know these new attributes will generate questions, so here's an FAQ that we hope covers most of\nthose.\n\nDo I need to change my existing nofollows?\n------------------------------------------\n\n\nNo. If you use `nofollow` now as a way to block sponsored links, or to signify that you\ndon't vouch for a page you link to, that will continue to be supported. There's absolutely no need\nto change any `nofollow` links that you already have.\n\nCan I use more than one `rel` value on a link?\n----------------------------------------------\n\n\nYes, you can use more than one `rel` value on a link. For example,\n`rel=\"ugc sponsored\"` is a perfectly valid attribute which hints that the link came\nfrom user-generated content and is sponsored. It's also valid to use `nofollow` with\nthe new attributes---such as `rel=\"nofollow ugc\"`---if you wish to be\nbackwards-compatible with services that don't support the new attributes.\n\nIf I use `nofollow` for ads or sponsored links, do I need to change those?\n--------------------------------------------------------------------------\n\n\nNo. You can keep using `nofollow` as a\n[method](/search/docs/essentials/spam-policies#link-spam)\nfor flagging such links to avoid possible link scheme penalties. You don't need to change any\nexisting markup. If you have systems that append this to new links, they can continue to do so.\nHowever, we recommend switching over to `rel=\"sponsored\"` if or when it is convenient.\n\nDo I still need to flag ad or sponsored links?\n----------------------------------------------\n\n\nYes. If you want to avoid a possible [link\nscheme action](/search/docs/essentials/spam-policies#link-spam), use `rel=\"sponsored\"` or `rel=\"nofollow\"` to flag these\nlinks. We prefer the use of `sponsored`, but either is fine and will be treated the\nsame, for this purpose.\n\nWhat happens if I use the wrong attribute on a link?\n----------------------------------------------------\n\n\nThere's no wrong attribute except in the case of sponsored links. If you flag a UGC link or a\nnon-ad link as `sponsored`, we'll see that hint but the impact---if any at\nall---would be at most that we might not count the link as a credit for another page. In this\nregard, it's no different than the status quo of many UGC and non-ad links already marked as\n`nofollow`.\n\n\nIt is an issue going the opposite way. Any link that is clearly an ad or sponsored should use\n`sponsored` or `nofollow`, as described above. Using `sponsored`\nis preferred, but `nofollow` is acceptable.\n\nWhy should I bother using any of these new attributes?\n------------------------------------------------------\n\n\nUsing the new attributes allows us to better process links for analysis of the web. That can\ninclude your own content, if people who link to you make use of these attributes.\n\nWon't changing to a \"hint\" approach encourage link spam in comments and UGC content?\n------------------------------------------------------------------------------------\n\n\nMany sites that allow third-parties to contribute to content already deter link spam in a variety\nof ways, including moderation tools that can be integrated into many blogging platforms and human\nreview. The link attributes of `ugc` and `nofollow` will continue to be a\nfurther deterrent. In most cases, the move to a hint model won't change the nature of how we treat\nsuch links. We'll generally treat them as we did with `nofollow` before and not\nconsider them for ranking purposes. We will still continue to carefully assess how to use links\nwithin Search, just as we always have and as we've had to do for situations where no attributions\nwere provided.\n\nWhen do these attributes and changes go into effect?\n----------------------------------------------------\n\n\nAll the link attributes, `sponsored`, `ugc`, and `nofollow`, now\nwork today as hints for us to incorporate for ranking purposes. For crawling and indexing\npurposes, `nofollow` will become a hint as of March 1, 2020. Those depending on\nnofollow solely to block a page from being indexed (which was never recommended) should use one of\nthe much more robust mechanisms listed on our\n[Learn how to block URLs from Google](/search/docs/crawling-indexing/control-what-you-share)\nhelp page.\n\n\nPosted by [Danny Sullivan](https://mastodon.social/@searchliaison) and\n[Gary Illyes](https://garyillyes.com/+)"]]
