The wiring diagram which as used in the most of the European countries.
This is applicable to both cars and their trailers as well as motorcycles with their trailers.
Sometimes you will find the 13 pole connection, which is practically the same, but with a few more connections.
An extra is the continuesly 12V connection and cooler connection available.

It is by the way recommended for most motorcycles to use the wiring below :
- 1L Yellow Direction Indicator Left
- 6/54 RED Braking lights
- 5/58 BRUIN Rear Light (split this in the trailer, as the trailer has two lights and a motorcycle just one)
- 4/R GREEN Direction Indicator Right
- 3/31 BLACK Ground

It can happen that you will find an American made connection on the trailer you've imported (there is a bigger market for trailers there):

I like these more, because they're less bigger, but that's a personal thing.