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 using/script-fu-tutorial.xml.
segmentedlist : in dialogs/path-dialog.xml for a n columns list.
Here is a diagram I often use.