Manual:$wgHTCPPort/en

Details
UDP/IP port to which to multicast HTCP requests, originally used with. Both were deprecated in MediaWiki 1.20.0; use  in MediaWiki 1.20.0 and   for MediaWiki 1.22 and subsequent.

As of MediaWiki 1.23 the old variables are still supported (by being copied to their successors in ) but are obsolete.