I didn't found the thread about it, but I really don't understand how the
fields are sorted for displaying.
It seems it's a mix of custom field name + Field Label + Heading and maybe
I've created 15 fields, named ndp_1 to ndp_15, and while they appears under
the same title thanks to identical Heading name, they are not at all in
alphanumerical order... then which parameter is used here to display them?