US and UK terminology are different. In the US, we count the number of branches, so a “three-way” has two switches and the light. A “four-way” has three switches and the light.
In the UK, they just count the number of switches. So a “two way” has two switches and the light. A “three-way” has three switches. Etc
The FAQ uses US terminology and discusses US wiring. I’m assuming that’s what applies to you, but if not let us know.
The basic wiring concepts for three ways and four ways and N Ways are the same, so it helps to learn those first. (For example, in the US wire colors are not usually mandated by law except for the ground and so any branch can be any color. You need to map the circuits first. So it doesn’t help to know that there are two white wires unless we know exactly what circuit segments those are on.)
And there is discussion in the FAQ of four ways as well. Some of the diagrams are four ways. So people there should be able to help you. 
