What is the purpose of this braze-on? I'm wondering what the purpose of the braze-on pictured below is? It's on the non-drive side of my fork. I thought it could have something to do with racks, but then I figured they would put one on both sides.  It could be used for a cable-guide for disc brakes, but my fork doesn't have disc tabs.  It seems like it's situated too low to be a cable guide for V-Brakes.  The bike is a touring bike, and the fork does have rack mounting holes, if that will give any clues to it's use.  

Update

It's the factory fork from a 2011 Devinci Caribou. I think I've seen disk versions, but they are older, all their newer ones have cantilevers, no option for disks. It's not threaded, and there is no split.  I may just be a wire-guide for whatever you choose to use it for, like a dynamo or speedometer. However, I think most wired speedometers are hard wired between the sensor and the computer, so I don't know how you would thread the cable through with the hardware on each end.
My thinking is that it is a brazed on guide for dynamo hub wiring. A touring bike like the Devinci Caribou would likely have provisions for things like dynamo lighting (I think that it'd be more likey that this was the case than someone erroneously adding a disc brake cable guide on a non-disc fork.) Typical braze-ons look like this:




As you can see there are a few different types. Some look like brake housing guides while others are unmistakably for flexible wires from a hub generator. As per the question of whether dynamo hubs have wires on one side or the other, I searched through Peter White's endless information on dynamo lighting and learned that:


  If you have an older SON28 hub with a black painted center section, SONXS, SONXS100, SON20R or SONdelux it makes no difference which way you align the hub in the fork. And with the new SON hubs from 2012, you again have the freedom to place the hub in either orientation. The conectors can be on either side of the bike.


This is just for Schmidt dynamo hubs, but I'd imagine that there are examples elsewhere.