add compat matrix

Author: helloimalastair

src/content/docs/r2/api/s3/api.mdx

@@ -28,6 +28,18 @@ When using the S3 API, the region for an R2 bucket is `auto`. For compatibility
 
 This also applies to the `LocationConstraint` for the `CreateBucket` API.
 
+## Checksum Types
+
+Checksums have an algorithm and a [type](https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html#ChecksumTypes). All checksums don't necessarily support all types.
+
+| Checksum Algorithm        | `FULL_OBJECT` | `COMPOSITE` |
+| ------------------------- | ------------- | ----------- |
+| CRC-64/NVME (`CRC64NVME`) | ✅            | ❌           |
+| CRC-32 (`CRC32`)          | ❌             | ✅          |
+| CRC-32C (`CRC32C`)        | ❌             | ✅          |
+| SHA-1 (`SHA1`)            | ❌             | ✅          |
+| SHA-256 (`SHA256`)        | ❌             | ✅          |
+
 ## Bucket-level operations
 
 The following tables are related to bucket-level operations.

src/content/release-notes/r2.yaml

@@ -7,7 +7,7 @@ productAreaLink: /workers/platform/changelog/platform/
 entries:
   - publish_date: "2025-07-03"
     description: |-
-      - The CRC64NVME Checksum algorithm is now supported for both single and multipart objects. This also brings support for the `FULL_OBJECT` Checksum Type on Multipart Uploads.
+      - The CRC-64/NVME Checksum algorithm is now supported for both single and multipart objects. This also brings support for the `FULL_OBJECT` Checksum Type on Multipart Uploads.
   - publish_date: "2024-12-03"
     description: |-
       - [Server-side Encryption with Customer-Provided Keys](/r2/examples/ssec/) is now available to all users via the Workers and S3-compatible APIs.