Just in case you were serious (no joke icon detected), in the UK a "two way" lighting circuit usually means one where two switches operate the same light. Similarly, "three way" etc.
The "end" switches (i.e. both in a two-way) are what would normally be termed "changeover" switches - with a common and two "lives", one at a time of which is connected to the common depending on the position of the switch.
The "middle" switches (in a more-than-two-way) are crossover switches where if "A" and "B" are your inputs with "P" and "Q" as outputs, in one switch position A connects to P and B connects to Q but in the other, A connects to Q and B connects to P.
This type of arrangement is most often found operating one or both of the hallway lights at the top and bottom of a staircase so that you can turn the light on before you go up, and off when you get to the top (or whatever).
Here are some diagrams and note that the recommendation is to use the "three wire" variants (at the bottom of the page) these days (hence the use of 3&E cable), as they avoid awkward current loops which can interfere with (for example) hearing aids on the "T" setting, and they discourage the use of "borrowed neutrals" which another poster has referred to earlier.
M.
Biting the hand that feeds IT
