Manual:$wgRCEngines

Details
Legacy mapping from URI schemes to RCFeed subclasses.

Used for (in RecentChange::factory ) to determine which class to use if  is not set, but  is.

This variable was introduced as and was renamed to  in MediaWiki 1.22 alpha.

Usage
This variable is an associated array mapping the URI protocol to the fully qualified class name that will handle that protocol.

This represents MediaWiki's built-in engine for sending RC updates over a UDP connection. More engines can be added by adding more keys or overriding existing ones.