ICS Distribution of Source Files - no rendition

When using ICS for distribution of native files (no renditions) job monitor dialog shows "Reference Mirroring" status and implies reference files are included in the distribution (more files than the Saved Search are getting distributed) so I'm guessing Reference Mirroring means references are getting distributed and attachments repaired.  I don't find any documentation/discussion about this in ProjectWise Help for ICS or in this Forum.

Where do I find settings to control reference file behavior in a Distribution Job.  I need Distribution jobs that include references and Distribution jobs that do not.

Thank you