If I use the following command command:

/give @p minecraft:tipped_arrow 1 0 {CustomPotionEffects:[{Id:8,Amplifier:0,Duration:3600}]}

I would expect to get an "Arrow of Leaping".
Instead I get an arrow Identical in every way to the arrow of leaping, (colour, effect, duration etc) but named "Arrow of Splashing"

I would even have expected them to be named according to effect if they had a different duration, amplifier or were of an effect currently absent from the creative menu, but that's less significant.