Forwarding to the list ---------- Forwarded message --------- From: <[email protected]> Date: Thu, Aug 13, 2026 at 2:41 AM Subject: AW: Descriptive vs. normative language in CP/CPS documentation To: <[email protected]>, <[email protected]> Cc: <[email protected]>
Hi Ben, Aaron, from the practical experience we are currently having, as we are rebuilding our CP/CPS structure from an overarching CP (with lots of RFC 2119 keywords ) and specific CPS to single purpose CP/CPS, I agree with Aaron, that a combined CP/CPS is nearly identical to a standalone CPS without RFC 2119 keywords. Our draft of the “CP portion” in Section 1.1 is currently something like this: *This document is the *CP/CPS TLS* ... * *In the structure of the [RFC3647], it describes the implementation of all relevant requirements of <List of all relevant laws and specifications, in our case EU and German law, ETSI, CA/Browser Forum, Root Stores, CCADB>* *… confirms compliance with all relevant requirements of the current version of the above-mentioned documents. In the event of a conflict between this document and the above documents, the provisions of the above documents shall prevail …* But in the following, the language is generally descriptive rather than normative. There may be a few exceptions, e.g., in chapter 9.6.3 and 9.6.4, where subscribers and relying parties are obliged to comply with certain requirements and thus the language can be, e.g., "subscribers must guarantee..." or "relying parties should...". But I'm not sure about that yet, as it could also be descriptive, e.g. "The requirements... are described in the Terms of Use" Kind regards Stefan *Von:* 'Ben Wilson' via [email protected] < [email protected]> *Gesendet:* Donnerstag, 13. August 2026 06:26 *An:* Aaron Gable <[email protected]> *Cc:* [email protected] <[email protected]> *Betreff:* Re: Descriptive vs. normative language in CP/CPS documentation Thanks, Aaron. I agree that the absence of an RFC 2119 keyword does not make an otherwise applicable CPS statement nonbinding. A CPS must describe the CA’s practices, and a CA is expected to operate consistently with such descriptions. Your recommendation that CPS documents contain no RFC 2119 keywords—and that the CP portion of a combined CP/CPS be limited to identifying the external policies with which the CA complies—is a broader proposal. I would be interested in hearing whether other CA operators, auditors, root store operators, and community members agree with that approach. I also welcome everyone's thoughts on how Mozilla should evaluate whether any particular CPS provision constitutes an implementation commitment. Thanks, Ben On Wed, Aug 12, 2026 at 6:41 PM Aaron Gable <[email protected]> wrote: Hi all, I'll reiterate my previous position: Policies are set by the PKI in which the CA operates; practices are described by the CA. Having each CA write its own CP has always been a category error. CP documents are *prescriptive*, and rely extensively on RFC 2119 keywords. CPS documents are *descriptive*, and should contain zero uses of the RFC 2119 keywords. In my opinion, a combined CP/CPS should be nearly identical to a standalone CPS, and contain no uses of RFC 2119 keywords. The CP portion of a combined document is just the paragraph at the top stating conformance to the Baseline Requirements (as required by BRs Section 2.2 <https://github.com/cabforum/servercert/blob/main/docs/BR.md#22-publication-of-information>) and other root program policies (as required by the Chrome Root Program Policy Section 1.1.3 <https://googlechrome.github.io/chromerootprogram/#113-chrome-root-program-participant-policies>, among others). With that context, my responses to Ben's specific questions are inline: On Sun, Aug 9, 2026 at 11:11 AM 'Ben Wilson' via [email protected] <[email protected]> wrote: Does a CPS statement commit a CA to a practice even if it does not use words such as MUST, each, or every? It is my opinion that a CPS or combined CP/CPS statement* definitely does* commit a CA to a practice even when the statement does not use MUST / SHALL / etc. Other words like "each" or "every" are more ambiguous. That gets into your other questions about ordinary meaning, drafter's intent, and genuinely unclear statements. What should be Mozilla's process or criteria when a CPS provision is identified as ambiguous or unclear? (E.g. ordinary meaning, the surrounding text, certificate profiles, applicable requirements, actual issuance practices, or a CA's or drafter's intent.) I think that Mozilla should make a public judgement call as to whether the ambiguity is sufficient to require an incident report. I don't think there's a great objective scale against which to make this judgement. One can imagine things like "a reasonable reader" (similar to the US legal system's "reasonable person") being invoked, but I don't know exactly how to structure that. At the end of the day, Mozilla is the entity that has the ability to close Bugzilla tickets, so Mozilla is the entity that has to decide -- in public -- whether the ticket gets to be closed or not. Should Mozilla’s CP/CPS guidance clarify the situations in which descriptive statements would be considered commitments, and should we explain how to handle genuinely unclear statements? I think that Mozilla should require that CPS documents contain no RFC 2119 keywords, and that combined CP/CPS documents be formatted as I described above: as a CPS, plus an additional paragraph stating adherence to external CPs. This will make it abundantly clear that even descriptive statements are binding, because descriptive statements are the only kind that will be present. Aaron -- You received this message because you are subscribed to the Google Groups " [email protected]" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/mozilla.org/d/msgid/dev-security-policy/CA%2B1gtabDQEJQ42gkPFMrqSeLFj56yqQzOV43hUkJwxGrUFXiPA%40mail.gmail.com <https://groups.google.com/a/mozilla.org/d/msgid/dev-security-policy/CA%2B1gtabDQEJQ42gkPFMrqSeLFj56yqQzOV43hUkJwxGrUFXiPA%40mail.gmail.com?utm_medium=email&utm_source=footer> . -- You received this message because you are subscribed to the Google Groups "[email protected]" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/mozilla.org/d/msgid/dev-security-policy/CA%2B1gtaZ%2B9%2Bt56fNxHte6pdSEoG5DG5Qga8AO3aYDgMsR-EZSPA%40mail.gmail.com.
