diff --git a/storage-format-versions.md b/storage-format-versions.md
index a6075b2..feaae09 100644
--- a/storage-format-versions.md
+++ b/storage-format-versions.md
@@ -62,17 +62,23 @@ Candidate changes for storage format 0.5 (container format 0.3); none is agreed
 Each row is a storage format version: what a `spatialdata` release writes, and the version of the
 abstract data model it encodes.
 
-| Storage format | Data model | `spatialdata` writes | container | raster | shapes | points | tables | Zarr | OME-Zarr (NGFF) |
-|----------------|------------|----------------------|-----------|--------|--------|--------|--------|------|-----------------|
-| **0.4** | **1.0** | ≥ 0.6.0 (default) | **0.2** | **0.3** | **0.3** | **0.2** | **0.2** | v3 | 0.5 (`"0.5-dev-spatialdata"`) |
-| 0.3 | 1.0 | 0.4.0 – 0.5.x; ≥ 0.6.0 (container 0.1 on request, deprecated) | 0.1 | 0.2 | 0.2 | 0.1 | 0.1 | v2 | 0.4 (`"0.4-dev-spatialdata"`) |
-| 0.2 | 1.0 | 0.2.2 – 0.3.x | 0.1 (recorded from 0.3.0) | 0.1 | 0.2 | 0.1 | 0.1 | v2 | 0.4 (`"0.4"`) |
-| 0.1 | 1.0 | < 0.2.2 | 0.1 (not recorded) | 0.1 | 0.1 | 0.1 | 0.1 | v2 | 0.4 (`"0.4"`) |
+| Storage format | Data model | `spatialdata` writes | container | raster | shapes | points | tables | Zarr | NGFF version string |
+|----------------|------------|----------------------|-----------|--------|--------|--------|--------|------|---------------------|
+| **0.4** | **1.0** | ≥ 0.6.0 (default) | **0.2** | **0.3** | **0.3** | **0.2** | **0.2** | v3 | `"0.5-dev-spatialdata"`<br>NGFF 0.5 + draft RFC-5 (transformations)[^ngff-compliance] |
+| 0.3 | 1.0 | 0.4.0 – 0.5.x; ≥ 0.6.0 (container 0.1 on request, deprecated) | 0.1 | 0.2 | 0.2 | 0.1 | 0.1 | v2 | `"0.4-dev-spatialdata"`<br>NGFF 0.4 + draft RFC-5 (transformations)[^ngff-compliance] |
+| 0.2 | 1.0 | 0.2.2 – 0.3.x | 0.1 (recorded from 0.3.0) | 0.1 | 0.2 | 0.1 | 0.1 | v2 | `"0.4"`<br>NGFF 0.4 + draft RFC-5 (transformations)[^ngff-compliance] |
+| 0.1 | 1.0 | < 0.2.2 | 0.1 (not recorded) | 0.1 | 0.1 | 0.1 | 0.1 | v2 | `"0.4"`<br>NGFF 0.4 + draft RFC-5 (transformations)[^ngff-compliance] |
 
 A container 0.2 store holds only the element versions in the first row. A container 0.1 store can
 hold any of the element versions in the other rows; stores without a container version are read as
 container 0.1. `spatialdata` reads every combination listed here.
 
+[^ngff-compliance]: Not compliant with any released NGFF version: the raster metadata follows the
+    listed NGFF version except for the coordinate transformations, which follow the draft of RFC-5.
+    The recorded `"0.4"` of raster 0.1 therefore overstates compliance; from raster 0.2 the
+    `-dev-spatialdata` suffix marks the deviation. We aim for compliance with NGFF 0.6, which is
+    expected to adopt RFC-5 (see {ref}`storage-next`).
+
 Storage format 0.3 is written by `spatialdata` 0.4.0 – 0.5.x and, on request, by `spatialdata`
 0.6.0 and later. Both write the same container, element, Zarr and NGFF versions; stores written by
 the later releases differ only in ways that change no version, such as per-level translations,