Even though true, it is still confusing to the media to have two competing numbering systems on the same page $ w3m -dump https://debconf18.debconf.org/ | grep 1[89]|s DebConf18 The 19th Debian Conference will be held in Hsinchu
So I would move such facts to a history page, and just present a single numbering scheme to the public. Most people will otherwise perceive it as an error and dismiss the conference as not even having enough staff to proofread its own pages.
