As far as I can remember ( there'll be an expert along in a moment ) the only way I could tell them apart was in the flesh and by using a short length of brake cable marked at 32mm from the barrel adjuster. This is how much cable a V brake lever will pull. Caliper and cantilever brake levers only pull 22mm. Hope this helps. The tree gag was about how ineffectual the non-V levers are when paired to V brakes.