In my experience with Etomite/MODx, there has never been a "folderonly" option. Instead, you can work with folders in a couple of ways. First, any document can be turned into a folder at any time simply by marking the ’Folder’ checkbox in the document’s Page Settings. A document will also automatically become a folder if you simply move another document to it as a child page.
Now...what I think you want is a way to have a folder but not one that shows up in the main menu, right? That’s simple...and can be done in two ways now. As with all versions of Etomite/MODx, you can simply ’unpublish’ a folder by unchecking the ’Published’ box in the folder’s Page Settings. This will keep the folder from showing up in the main menu and will keep it from being cached as well. The ’Published’ setting can be changed at any time, thus making it a document as well as a folder.
A new feature in TP3 is a ’Show in menu’ option. For each document/folder, a new checkbox appears in the General Document Settings. By default, the checkbox is marked for any new document or folder. However, let’s say that you still want your folder to be published but don’t want it showing up in the main menu. Unchecking this box with the folder still published will give you just that.
As you can see, it’s just a matter of understanding the subtle nuances and features as well as what each setting does for a given document or folder. Granted, I can understand how this can be a little confusing at first for newcomers. In the future, I’m sure we’ll see more robust documentation that will explain this even further. Then, whenever someone posts a question such as this, we can always say "RTFM!!". LOL!
Hope this helps!
L8R!