"This is the largest, best and most viewed O Gauge Train Forum on the internet!"
"Uh Oh! This is the largest, most unmanageable O Gauge Train forum on the internet!"
Even 3 Rail Scale, the description simply restates the title and uses the 3RS acronym, without saying what it actually is defined as!
On the 3-Rail Scale Forum, there is a "sticky" titled "What is 3-Rail Scale", with 4 pages of discussion. Should be plain enough for any new person visiting that forum.