The VERSIONCHECK: Keyword
The VERSIONCHECK: keyword corresponds to xsubpp's -versioncheck and -noversioncheck options. This keyword overrides the command line options. Version checking is enabled by default. When version checking is enabled the XS module will attempt to verify that its version matches the version of the PM module.
To enable version checking:
    VERSIONCHECK: ENABLE
To disable version checking:
    VERSIONCHECK: DISABLE