WWE Hardcore Championship
The WWE Hardcore Championship was a hardcore wrestling championship in the WWF (now WWE) which was contested under "hardcore" rules (no disqualifications, no countouts, and pinfalls count anywhere). In the latter part of the title's history, a rule was implemented allowing anyone to challenge the champion at any place or time, provided a referee was present (dubbed the "24/7 rule").
Source: Wikipedia — WWE Hardcore Championship (CC BY-SA 4.0)