From Ghent PDF Workgroup.
The Ghent PDF Workgroup (GWG) has released the first "Proof of Preflight" specification designed to verify PDF file integrity throughout the production workflow. The spec allows users to review a PDF file’s preflight audit trail at any time, verifying which GWG preflight specification was used to preflight the file and also the outcome of the preflight check.
Its "open" design makes it interoperable across various vendor workflows. The Proof of Preflight Specification can be downloaded for free.
THE GHENT WORKGROUP