Thanks Jeroen!
I suppose it is the wiring diagram of the X45. No clue (very little) how to read it. (yet)

But I'll find out!
Yes.
The colors correspond to the wires going to the PCB inside the stick.
the numbers correspond to pins on the throttle's connector.
SH1/SH2 stick hats 1 and 2
S1-S6 stick switches 1 to 6
TH3/TH4 throttle hats 3 and 4
MU/MD mode up and down
AU/AD aux up and down
T7/T8 throttleswitch 7 and 8
JX/JY joystick X and Y axis
TH throttle axis
RD rudder axis
R1/R2 rotaries 1 and 2
The triangles are diodes to prevent key ghosting.
Rectangles are resistors.
U, D, L, R ect are the directions of the hats.
UL, UR etc are the diagonal directions and a combination of up/down and left/right.
The switches are laid out in a matrix.
The analog axes use pots.
They share two lines in common on the outer pins. (5V and ground)
The middle wiper pin has a seperate line for each pot.