No, the default is "off", but keep in mind that if a category has NO restrictions at all, then it is globally accessible.
Does @User work with non-latin letters?
I'm currently working on a language community, in which there will be quite a few alphabet scripts, and was wondering if @ works with non-latin alphabets (e.g. @경은 will point to the user 경은)
@julian Close enough. Your point is made.