The layers a page's display list can hold, so that a viewer can redraw the annotation and form-field overlays without rebuilding or re-rasterizing the page content. A list holding several layers paints them in this order.
[Flags]
public enum DisplayLayers
ISO 32000-2 §12.5 (annotations are drawn over the page content, §12.5.5) and §12.7 (an interactive form's fields appear through their widget annotations, §12.5.6.19). Splitting widgets from the other annotations changes their relative order on the page: every field is drawn over every other annotation, which is what a viewer that shows fields as a layer of their own does.
kind:method, kind:property, kind:ctor. Press Esc to clear.AllContent, then annotations, then form fields: the whole page as a viewer shows it.AnnotationsThe appearances of every annotation but widgets (ISO 32000-2 §12.5.5), in Annots order.ContentThe page's content streams (ISO 32000-2 §7.7.3.3, Table 31, Contents).FormFieldsThe appearances of widget annotations (ISO 32000-2 §12.5.6.19, §12.7), in Annots order.NoneNothing: the list is empty.