offer and more about why another school is a bad choice.

For the most part, it can be hard to negative recruit because there is a comparison that can be made to your school across the board. So even something like, "XXX doesn't offer a degree in the field you're interested in; we do" is not negative recruiting because you are simply making a comparison between your school and another school. However, there are times when either their is no ability to compare two characteristics of the schools. The Honor Code is a good example, but you could (I guess) see other examples. I just can't think of any right now.