PDF/A documents no longer identified

[dgn]

In upgrading from Exiftool 10.00 to 11.01 for use within the File Information Tool Set (http://fitstool.org) I have noticed a change in the identification of PDF documents. Whereas the old version would return metadata indicating a PDF/A document the current version only identifies the document as PDF. Here is the relevant tool output:
v.10.00
    <SchemasPrefix>pdfaid</SchemasPrefix>
    <SchemasSchema>PDF/A ID Schema</SchemasSchema>
v.11.01
    <SchemasPrefix>pdf</SchemasPrefix>
    <SchemasSchema>Adobe PDF Schema</SchemasSchema>

Any help resolving this greatly appreciated.

[Phil Harvey]

I have no idea where the "pdfaid" comes from.  Can you provide a sample PDF file and an example exiftool command that shows this with ExifTool 10.00?

- Phil

[dgn]

A PDF/A document is attached.
I realized afterwards that I posted "post-processed" data rather than Exiftool raw output.

Using v.10.00 of Exiftool the following relevant data was output for the attached file:
Schemas Prefix                  : pdfaid
Schemas Schema                  : PDF/A ID Schema

Using v.11.01 the same data points:
Schemas Prefix                  : pdf
Schemas Schema                  : Adobe PDF Schema

I don't know why/how "pdfaid" is being output for all PDF/A documents.
However, with v.11.01 I have noticed a new data point being output for PDF/A documents (but not for simple PDF documents):
Conformance                     : B
(for type 1a PDF/A documents this value is "A")

In the past we used the value of  "Schemas Schema    : PDF/A ID Schema" to identify a document as PDF/A.
My question is whether this "Conformance" value can now be reliably used to identify PDF/A documents.

Thanks in advance for your help.

[Phil Harvey]

The confusion is due to the fact that multiple tags exist with the same name.  Use the -a option to see them all:

Code Select Expand

> exiftool ~/Desktop/PDFa_equations.pdf -schemasprefix -schemasschema -a
Schemas Prefix                  : pdf
Schemas Prefix                  : xmpMM
Schemas Prefix                  : pdfaid
Schemas Schema                  : Adobe PDF Schema
Schemas Schema                  : XMP Media Management Schema
Schemas Schema                  : PDF/A ID Schema

Without -a, only one will be returned.  The difference in the preferred tag came in ExifTool 10.30 when the priority of unknown XMP tags was lowered.

- Phil

Edit:  Looking more closely at the XMP in this file, the "schemas" metadata is a bag of structures.  ExifTool should probably treat this as a list-type tag, but currently unknown tags are not handled this way.  If this changes, future versions of ExifTool may extract this SchemasPrefix as "pdf, xmpMM, padfaid".

[dgn]

Thanks, Phil, this information has been very helpful.