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+# Feed handler plugins
+
+!!! warning
+
+    Unless you have a strong need for these plugins, using them is not recommended. If
+    you do use them, at least don't enable them for all feeds.
+
+Some plugins utilize global per-feed content hooks which either modify fetched
+feed XML data (i.e. fixing broken XML) or even generate it entirely, for tt-rss
+to process, for websites that don't actually provide RSS feeds.
+
+While having this ability available for plugins is valuable there are several
+downsides:
+
+1. This entirely bypasses rate-limiting and article duplicate checking done
+   during normal feed update process. A badly written plugin using
+   <code>HOOK_FETCH_FEED</code> may cause your tt-rss feed to keep updating
+   feeds indefinitely, processing all articles every time, causing unnecessary
+   CPU load on your server.
+
+2. If you have full text content plugins enabled, this may cause excessive load
+   on origin server, because your tt-rss instance is going to scrape site
+   content for every provided article on every feed update.
+
+This may result in your tt-rss instance being banned by origin servers for
+causing excessive load and/or your VDS being suspended for suspected bad
+behavior.
+
+Additionally, tt-rss being blacklisted by feed publishers may negatively affect
+other users.