ID's
ID's, which identify commands and are used when pressing the F1 key in the GIMP interface, are in https://git.gnome.org/browse/gimp/tree/app/widgets/gimphelp-ids.h
XML Tags Examples
procedure: in using/web.xml.
table: in toolbox/tools-painting.xml.
programlisting: in filters/web/slice.xml.
segmentedlist: in dialogs/path-dialog.xml for a n columns list.
Here is a diagram I often use.