If you want to upload adult content to scribd, it must be added to the adult group. If you want to upload anything else, it doesn't have to be in a group at al

If you want to upload adult content to scribd, it must be added to the adult group. If you want to upload anything else, it doesn't have to be in a group at all. At least, that's the way I understood the comment. If you only measure groups, you're ignoring the vast majority of uploads which are not added to anything.