Step 1: In your OVAL check, you define which platforms the check is
written for. This is done by the <affected> stanzas, such as:
> <affected family="unix">
> <platform>Red Hat Enterprise Linux 6</platform>
> </affected>
Step 2: When an SCAP interpreter parses each OVAL rule, it will parse
the <affected> tag above. For each <platform> listed, it will find the
associated <cpi-item> to find what <check> needs to be ran. This will
tell the SCAP interpreter if the OVAL rule is applicable for the system
being scanned.