Predefined Profiles and result view for Processing Steps
pdfToolbox has two checking Profiles related to Processing Steps:
"List Processing Steps metadata information”
Provides information about what Processing Steps metadata is present in a PDF file, whether any layers are empty etc.
“Verify compliance with Processing Steps (ISO 19593-1) for packaging and label”
is an exact implementation of all requirements of the standard. It allows to check whether the PDF complies.
All Checks related to Processing Steps treat empty layers, i.e. layers without any objects, as not present. This makes sense because when analyzing presence of Processing Steps information an empty layer has the same consequences as if the whole layer would not be present.
In the hits section in result view page, objects are listed but not layers. Processing Steps information is only available in the second level and since many objects will have the same metadata, this does not provide an overview about what metadata is present.
But a nice overview is provided below in Overview / Layers: