> 28) Lines 624 and 609: Probably both should say "RFC ZZZ", and then
> put a note to the RFC Editor to replace RFC ZZZ with the RFC number of
> this document when it is published.
> 29) Line 627: I would probably remove this comment as it does not
> really add anything.
> 30) Line 629: Reusable groupings, like type definitions etc, should be
> defined before they are being used. This makes the module definition
> cleaner and more easy to read. Please move the definition of
> voucher-artifact-grouping before your top level statement.
> 31) 31a) Line 632: I don't understand this statement. What do you
> mean with "grouping defined for future augmentations"?
> 31b) If you want to allow for future extensions, it would be good to
> indicate what you have in mind, specifically. Provide an example (not
> inside the data model definition, but in a subsequent section).