Category slugs should allow + and -

[noel]

Categories with duplicate names, but + and - in them are not allowed.

Example: I would like to create the categories A, A-, B+, B, B-, C+, C, etc. However, Wordpress will only allow me to create the initial A, B, C categories. When I go to create A-, B+, B-, C+, etc. I am told that they already exist. Is this just not something that is possible? Thanks!

[ionfish]

Plus signs are used in taxonomy intersections, so it makes sense not to allow them in taxonomy slugs.