When is a folder not a folder?

When it is a resource/x-turnitin-assignment.

update course_contents
set cnthndlr_handle = ‘resource/x-bb-folder’, main_data = NULL, text_format_type = ‘S’, offline_name = NULL, offline_path = NULL, start_date = NULL, title = ‘Assignments’
where pk1 = <offending item >