CTA support matrix: can someone explain "IMPORTANT: Retention is not supported when archiving to S3 cloud repositories."

Hello, 

Retention is only supported for ECS CAS. When tiering to ECS CAS, by setting a retention period the objects in the cloud can be locked from deletion until the period ends. If stub retention is enabled, the stub files in the source would be locked following the same time period.  

The Retention Period is a pre-requirement to Stub Retention. Reference the last two attributes for an Archive policy below.

For Dell EMC Unity, Dell EMC Unity OE 5.1 added support for stub retention with CTA 13.0 and later.

Setting the retention period and stub retention attributes in CTA for none ECS CAS repositories would have no effects and CTA would prevent the creation of such policy.