Evaluation structure & in SAP name range

What causes this issue?

The name you have chosen for your evaluation structure begins with "S".
However, evaluation structures beginning with "S" fall into the name
range that is reserved for SAP.

System Response

The evaluation structure cannot be created.

How to fix this error?

Choose a name for your evaluation structure that does not begin with
"S".

Error message extract from SAP system. Copyright SAP SE.