Thank you for the reply. I am a little confused though about this.
I have an ::xowiki::Form that has various fields for content to enable the creation of new FormPages that are automatically styled. One of the fields is an includelet specification field in which I am in this example putting the carousel includelet.
Instead of creating an instance of the FormPage with the folder that contains the images hard-coded into the includelet specification for every set of pictures, I would like to be able to provide the folder_id for the images to display from a value passed in the url.
Am I correct in understanding that I should create the minimal forms you describe above (which when allocated a category will naturally appear in the dropdown menu), and then include these forms in the page?
So essentially we would have a carousel embedded within a form, which itself is embedded in a form?