Merge pull request #1 from yarikoptic/rfc-2-updates

Add my re-review (ome#2) of RFC-2

rfc/2/index.md

@@ -134,6 +134,12 @@ This RFC is currently in RFC state (R6).
     - Google
     - 2024-09-11
     - [Accept](./reviews/3b/index)
+*   - Reviewer
+    - Yaroslav O. Halchenko
+    - yarikoptic
+    - Dartmouth College, DANDI Project
+    - 2024-09-11
+    - [Accept](./reviews/2b/index)
 ```
 
 ## Overview

rfc/2/reviews/2b/index.md

@@ -0,0 +1,25 @@
+# Review 2 (update)
+
+## Review authors
+This review was written by:
+- Yaroslav O. Halchenko (Dartmouth College, DANDI Project)
+
+## Summary
+
+Comments from the initial round of reviews were proposed, accepted (with minor tune ups after) in https://github.com/ome/ngff/pull/250 . The changes to RFC-2 in that PR are sufficient to update our recommendation from "Major changes" to "Accept".
+
+- Concern on compatibility with Zarr v2/OME 0.4 was largely addressed: it is now RECOMMENDED to maintain compatibility.
+- Concern on v2 and v3 co-existence was addressed by more explicit formulation that it is possible but NOT RECOMMENDED [^1], and that 0.5 SHOULD be treated preferentially in case of both v2 and v3 metadata co-existence.
+- Recommendation on separation of the "name" of the standard from the versioning was addressed by introduction of `ome` as the top-level key for the OME-NGFF metadata in zarr.json with a `version` key within that `ome` record.
+  - unfortunately the concept of "namespaces" is not yet formalized in Zarr itself, WiP in [ZEP004: Namespaces](https://github.com/zarr-developers/zarr-specs/pull/262/files).
+    So it would remain possible that changes in the future would be needed to align with Zarr's formalization of namespaces.
+- My questioning of the value to bundle together support of Zarr v3 and changes to metadata was largely addressed by addition to "Drawbacks, risks, alternatives, and unknowns": even without formalization of "Zarr namespaces" it would be useful to have `ome` as the top-level key for the OME-NGFF metadata in zarr.json.
+
+[^1]: according to [RFC 2119: Section 4](https://datatracker.ietf.org/doc/html/rfc2119#section-4), even though "NOT RECOMMENDED" is not explicitly listed among the list of key words, it is to be treated similarly to "SHOULD NOT", so we are fine here.
+
+Remaining concerns in the original review are addressed by stronger language around how applications should handle multiple versions and the usage of ‘ome’ as the top-level key for the OME-NGFF metadata in zarr.json.
+
+
+## Recommendation
+
+"Accept".