Naming convention &1 &2 is in the name range for SAP development partners

What causes this issue?

The entered naming convention &V1& &V2& lies in the name range for SAP
development partners.
Only SAP development partners may reserve partner name ranges which
must be within the project name range.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Cancel maintenance. Do not transport this entry.

Error message extract from SAP system. Copyright SAP SE.