內容簡介
304 Not Modified HTTP Header 是告訴訪問者網頁自上次訪問以來沒有任何更改。這很重要，因為如果沒有此標頭，訪問者可能每次都要重新下載您的網頁，進而減慢使用者體驗和您的網站速度。
通常，如果您沒有經過 HTTP 標頭傳遞 304 Not Modified HTTP Header，爬蟲將會從頭爬取整個網站，然後將您的網站內容與已經索引的內容進行比較，檢查是否有更新網站的內容。但是，這個過程會耗用大量的伺服器資源和頻寬。
您可以在這裡了解更多資訊。
在繼續閱讀之前
請注意，此外掛使用輸出緩衝，實際上由此外掛發送的 Etag 是網站緩衝內容的哈希值。如果您的網站使用伺服器端快取，此外掛可能會破壞快取功能。因此，在安裝和啟用之前，我建議您先閱讀常見問題解答。
外掛標籤
開發者團隊
原文外掛簡介
A 304 Not Modified HTTP Header tells your visitors that nothing has changed since their last visit. This is important as without this header visitors may be downloading your webpages from scratch each time, slowing down their experience and your site.
Generally if you do not pass 304 Not Modified HTTP Header through your HTTP header, crawlers will fetch your whole website and then compare the content of your site with the already indexed content to check whether anything new has been updated on your website or not. But this process consumes a lot of your server resource and bandwidth.
You can know more about it here.
Before reading any further
Before reading any further it is important to understand this plugin uses output buffering, in fact the Etag sent by this plugin is a hash of the sites buffered content. If your site uses server side caching this plugin may break the caching functionality. Therefore I suggest that you please make sure you have studied the FAQ, before installation and activation.
