Tonearm wiring termination---DIN, or RCA jacks?

Swamp, that seems like a very sensible solution. I suppose the wire could be enclosed in some type of sheath for added strength. Have you seen this done?

Good quality RCAs are superior to DINs. 'Swamp' also has a good solution.

I don't know precisely how it is configured in each case inside the arm wand, but several tonearm builders provide a one piece solution (clips to male RCAs) as an option. I know my Schroeder does. There are bare wires in the wand and then the outer sheathing begins at the base of the arm pillar. If you have a Rega arm you can even buy a rewire kit that is direct from clips to RCAs as shown
here.

I agree with the 1-piece wire approach whereby a single high-quality tonearm wire extends from the cartridge clips to the RCA plugs going into the preamp (or SUT). Mesch asked if any commercial tonearms do this, and the answer is Definitely! Each of my arms came that way---Triplanar,Schick and Siggwan. Typically the fine-gauge tonearm wire goes into a sheath a few inches from the arm with perhaps a ground wire inside which adds bulk and mass and makes the delicate wire much more durable. I have never had any problems with the wiring in my arms.

Re-wiring a tonearm can also be a nice sonic upgrade. I recently replaced the Cardas wiring in my Siggwan with something called "1877 Phono" wire, and this made a nice improvement in sound. The RCA plugs at the preamp end of the wire are also important. The Siggwan came with KLE Copper Harmony plugs, but swapping them out for KLE Absolute Harmony plugs made almost as much difference as the wire itself.

Direct wired RCA is best for low level signals.