Add clarifications

Author: RanVaknin

VERSIONING.md

@@ -26,7 +26,9 @@ The SDK versions all service clients (e.g. `S3`, `EC2`, `DynamoDb`, etc) and the
 
 **Best Practice: Use matching versions across all SDK modules.**
 
-The SDK supports limited mixed version combinations within the same minor version boundary only. Cross minor version mixing is not supported and may cause runtime exceptions when newer core components call methods that older service modules only implement as default stubs.
+The SDK supports mixed version combinations only within the same minor version boundary. Mixed version combinations create untested scenarios that are difficult to reproduce and debug. The SDK team cannot guarantee compatibility testing coverage for all possible version combinations, and issues may require upgrading to matching versions to resolve. 
+
+Cross minor version mixing is not supported and may cause runtime exceptions when newer core components call methods that older service modules only implement as default stubs.
 
 ### Supported Version Combinations
 
@@ -37,6 +39,8 @@ The SDK supports limited mixed version combinations within the same minor versio
 - ❌ **Not Supported**: Cross minor-version mixing (e.g., `sdk-core 2.34.x` with `s3 2.32.y`)
 - ❌ **Not Supported**: Old core + new service (causes compile-time failures)
 
+Use the [SDK BOM (Bill of Materials)](https://github.com/aws/aws-sdk-java-v2/?tab=readme-ov-file#importing-the-bom) to automatically manage compatible versions across all SDK modules and prevent version mismatches.
+
 ## Internal APIs
 
 Any API marked with either `@SdkInternalApi` or `@SdkTestInternalApi` is not subject to any backwards compatibility guarantee. These are meant to be consumed only by the SDK and may be changed or removed without notice. The SDK MAY bump the `MINOR` version when making such a change.