Code change:
Transparency Services MUST maintain Registration Policies. <del> Transparency Services MUST also maintain a list of trust anchors used to authenticate Issuers, which MAY be included in a registration policy statement.  For instance, a trust anchor could be an X.509 root certificate, the discovery URL of an OpenID Connect identity provider, or any other COSE compatible PKI trust anchor. </del> <ins> Transparency Services MUST also maintain a list of trust anchors, which SHOULD be used by Relying Parties to authenticate Issuers, and which MAY be included in a registration policy statement.  For instance, a trust anchor could be an X.509 root certificate, the discovery URL of an OpenID Connect identity provider, or any other COSE compatible PKI trust anchor. </ins> Registration Policies and trust anchors MUST be made transparent and available to all Relying Parties of the Transparency Service by

Related discussion:
text: Hi all, This PR comes from a place that agrees: If using an identity scheme, then yes, it must be used in maner consistent with that scheme, But aslo that There is no identity scheme we could all agree on as universally applicable or agreable, further, the space continues to evolve. And, The trustworthiness or otherwise of issuers identity, in the context of a transparency ledger, is temporal and subjective in nature. It's just a question of time frame. This means that regardless of registration time checks, relying parties, auditors and general consumers will have to re evaluate regardless. And will do so according to their own subjective context. Remembering that "It can never be assumed that some Issuers and some Transparency Services will not be corrupt.". And also "A Verifier SHOULD validate a Transparent Statement originating from a given Issuer" ... "and would not depend on any other Issuer or Transparency Services." It does seem obvious that, Syntactic validation of the issuer identity claims makes good sense and supports interoperability. But, Specifying a single identity scheme in the core architecture as "minimally required" does not meaningfully help interoperability when there is no single agreeable scheme, and especially when a TS may be used to underpin identity schemes themselves. Regarding the burden on Relying Parties and Auditors, The definition for "Relying Party" states "a Relying Parties consumes Transparent Statements, verifying their proofs and inspecting the Statement payload, either before using corresponding Artifacts, or later to audit an Artifact's provenance on the supply chain". IOW: Relying parties are already expected to deeply consider statements. Assessing the identity asserted by the issuer, at the time the artifact is being considered, seems to be a natural and useful part of that process. Registration Auditability: Requiring that Transparency Services "enough information is made available to Auditors" ... "to authenticate and retrieve the Transparent Statements" is essentially impossible to specify at this level, imposes un-bounded maintenance and storage issues on implementations, and represents a significant layering violation in the architecture.
Editors meeting: will wait 24hours for reviews, with merger if no objections.
Per the editors meeting, I've merged the discussed changes and resolved the discussed topics. I've opened to track the MUST/Should discussion, which wasn't part of this PR.