Oracle instance names must not contain Oracle version numbers.

Service names may be discovered by unauthenticated users. If the service name includes version numbers or other database product information, a malicious user may use that information to develop a targeted attack.

From SQL*Plus:

select instance_name from v$instance; select version from v$instance;

If the instance name returned references the Oracle release number, this is a finding.

Numbers used that include version numbers by coincidence are not a finding.

The DBA should be able to relate the significance of the presence of a digit in the SID.

Follow the instructions in Oracle MetaLink Note 15390.1 (and related documents) to change the SID for the database without re-creating the database to a value that does not identify the Oracle version.