We have a custom content type that extends folder called Enhanced folder. We've added some custom managed metadata columns and all. That seems to be working (except for this).
Using SPD we created a custom edit form for the Enhanced folder and arranged the data entry fields to make data entry easier. In the process we added a field control for the Page Content column. It was a mistake because the Enhanced folder content type definition does not include the Page Content column.
BUT...it seems to work!
Can anyone explain how just adding a column to the entry form allows that content type to use that column even if that column isn't part of the content type?
BTW, if you didn't follow the link above, adding the Page Content column to an extended folder type breaks using the web ui to create instances of that content type.