It seems that currently we have a tag called shockwave (but not shock_wave, curiously enough), which is marked a character. I'm guessing this has something to do with transformers? Anyway, it clashes with the usual meaning of the word shockwave / shock_wave, one of which should be aliased to the other, whilst the transformers ones should be qualified as shockwave_(transformers). I believe there are also soundwave, lightwave and others, which should get similar treatment.
tl;dr: shockwave & co. should be de-characterified, and someone who actually understands transformers should propose a sensible scheme for the characters.
Updated by a moderator