I have a grand-parent-category with several parent-category. Each groundchild means a specific method to process later. Parents should not be selected, it merely means to group the children together.
child_of to show the dropdown form. The parents shows up as a choice which can course confusing for users.
If I add
exclude = $parent_ids, the whole dropdown list gone.
I can throw error message or process to a default value if a user choosed a parent, but this is a way to frustrat my users. Is there any other way to make a dropdown without parent?