I have reviewed this document as part of the Operational 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. Summary: This document is mostly ready; idnits is clean, but I have one concern. I read through the document a couple of times, unfamiliar with PKCS, and while I found a few editorial tweaks, I was mostly struck with the lack of normative language in the draft. It was fairly nonexistent. I found that .. surprising. I read through the draft a second time, and only found it more surprising. I do like the approachable tone of the draft, and in particular, I'd let go the "SHOULD" for "it's our recommendation" - but there are several times where it's written "must be" or "must not be" and again, the normative nature of the text, although not written as such, stopped me cold in my reading tracks. I'd suggest the authors revisit those references, because to this reader, not being part of the WG discussion, I can't easily determine why they're not normative, when they read as such. Regards, Sarah