You can view examples in the help desk and Picture Gallery forums.
This allows sub-forums to be added to an existing forum.
This may be helpful for forums such as the NEC code topics when new code is adopted.Due to adoption of new code cycles, when do you know what code the question you are viewing applies to what code?
Note: Nesting sub-forums can get a little confusing if you are not aware of the feature. I will leave it to the moderaters to decide.