I have reviewed this document as part of the YANG doctors directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written with the intent of improving the operational aspects of the IETF drafts. Comments that are not addressed in last call may be included in AD reviews during the IESG review. Document editors and WG chairs should treat these comments just like any other last call comments. This document includes two YANG modules: - ietf-cwt-voucher@2018-02-07.yang - ietf-cwt-voucher-request@2018-02-07.yang These are relatively small modules consisting of a single grouping each, and are used to augment single leafs into a grouping from an external module (ietf-voucher). A couple of nits: - The modules use the 'cwt' acronym in their names, but that acronym is only spelled out in the Normative References section. Suggest spelling it out in the description field in the modules and in the draft itself. - Both modules have the same top-level description. Suggest revising the wording to describe the specific content of each module such that they are unique. - I would suggest running both modules through 'pyang -f yang' for consistent formatting. The diffs are related to whitespace, quotations and comments (including a modename in each module) - Sections 6.2.1. and 6.3.1. both provide YANG tree diagrams of the groupings defined. These groupings are defined in RFC8366 and only one of the leafs are defined in the local document. It might be worth pointing this fact out for clarity.