VLSC downloads are multi-edition ISOs. They contain both Standard and Datacenter, both Core and Desktop Experience. This is the gold standard for “non-evaluation.”
If the result is ServerStandardEval or ServerDatacenterEval , you are on the evaluation version. Windows Server 2016 Standard Iso Not Evaluation
: Use your purchased product key in the following command: VLSC downloads are multi-edition ISOs
If you already have a valid license key, you can access the full media through these official channels: Windows Server 2016 Standard Iso Not Evaluation