I agree: The term anti-E is both outdated, misleading, and incorrect. I repeated it, largely in an attempt to steer the OP from a term, though I did not elucidate this point.
Again, I fully agree: Saying "gray area" to some may indicate legality. In truth, gray area means no specific illegality, which means possible prosecution. The same gray area applies to Finaplix pellets for bovine. Some people, under some conditions, can legally buy and use Finaplix for cattle, and so it is available legally for sale both on the internet and in cattle stores. However, one could easily be prosecuted for it, being that the intended legal use is not met, and instead the illicit use is intended.
I appreciate the clarification, because people can and will misinterpret discussions on legality of importation, possession, etc. and can make serious errors because of this.