Your feed subscribers have already read your old posts or they\u2019ve been cached in their feed readers already. Stop wasting bandwidth and only return the posts published since supporting feed reader last requested a feed update.<\/p>\n\n
As a nice bonus, this plugin will decrease the number of false cache misses for all your feeds.<\/p>\n\n
This section addresses some known problems and some known solutions to those problems as well.<\/p>\n\n
Indeed, they may not be. The \u201cSyndication feeds show the most recent\u201d setting in WordPress is respected to avoid delta updates being used to extract all the content out of a website by providing a timestamp from a decade ago. Feed reader clients will generally check feeds often enough to receive all the deltas as they appear in the feed anyway.<\/p>\n\n
Please consider increasing the max setting limit now that you\u2019re using feeds with delta updates.<\/p>\n\n
Indeed, that can happen \u2013 but lets look at why it happens.<\/p>\n\n
Posts that have been published within the last week may reappear in a delta update if the post has been modified since the feed was last updated. Feed reader clients are expected to handled updated posts, and the delta update is expected to include updated posts.<\/p>\n\n
You can avoid pushing out minor post modifications, such as spelling corrections, and improve on caching by installing the Minor Edits<\/em> plugin<\/a>. This plugin will suppress changes to a post\u2019s modification time for minor updates.<\/p>\n\n Posts older than one week aren\u2019t considered \u201cnews worthy\u201d any longer and wouldn\u2019t be included in a delta update even with significant modifications.<\/p>\n\n\n No configuration is required or indeed possible.<\/p>\n\n\n Nobody asked about any of this, but I assume that at least some of you would be curious about this stuff.<\/p>\n Feed delta updates is a defacto standard based on RFC 3229 Delta encoding in HTTP<\/em> with the feed<\/em> extension. With delta updates to feeds, your syndication feeds will only return new or modified content to supported feed reader clients instead of giving them the entire feed including old entries they\u2019ve already retrieved. This reduces the bandwidth requirements as your feed will contain fewer posts when the feed reader client have already received the most recent version of an item in your feed.<\/p><\/dd>\n You can\u2019t really control this as it\u2019s up to the feed reader client and user preferences. You can, however, use the Atom, RSS, RDF, and anything else WordPress core classifies as a \u201cfeed format\u201d.<\/p><\/dd>\n Quite a few including FeedHQ<\/a>, Feed Notifier<\/a>, Internet Explorer, Jarr<\/a>, Liferea<\/a>, Microsoft Outlook, Miniflux<\/a>, Newsblur<\/a>, Newsbeuter<\/a>, Vienna<\/a>, and others. Please make sure you\u2019re running an updated version of your feed reader.<\/p><\/dd>\n\n
\/wp-content\/plugins\/delta-feeds<\/code> directory, or install the plugin through the WordPress plugins screen directly.<\/li>\n\n
Cache-Control: max-age=<seconds><\/code> header to provide a hint to clients as to how often they should be checking for new content. Use the Cache-Control plugin<\/a> to configure this header.<\/p><\/dd>\n