PDF metadata - source modified

[BitWyse]

Hi all.

During analysis of a PDF document I have encountered populated metadata named "source modified". The resulting metadata appears to be a timestamp, prefixed with a letter. The timestamp predates the creation of the document.

D:YYYYMMDDTTTTTT

I have searched the forum for any indicator of what relevance this information may have. Has anyone encountered it previously? Would appreciate any help.

[StarGeek]

Quite a lot of the tags that exiftool can read have no public documentation. Some have been deciphered only because of the efforts of the community at large.

Going through some of my PDFs, I can find this tag as PDF:SourceModified and XMP-pdfx:SourceModified. Neither of these are built in to exiftool and the XMP-pdfx group is the group of tags that are application specific tags (see XMP-pdfx tags). Additionally, this is the group where people can add their custom tags, so sometimes you will come across tags in this group that are completely unknown other than to the people who created them.

I checked ~6,000 pdfs I have and found this tag in only 27 of them. In those 27, these are the CreatorTool/Producer tags for them.

Code Select Expand

CreatorTool                     : Acrobat PDFMaker 11 for Word
CreatorTool                     : Acrobat PDFMaker 11 para Word
CreatorTool                     : Acrobat PDFMaker 15 for Word
CreatorTool                     : Acrobat PDFMaker 17 for Word
CreatorTool                     : Acrobat PDFMaker 18 for Word
CreatorTool                     : Acrobat PDFMaker 20 for Word
CreatorTool                     : Acrobat PDFMaker 21 for Word
CreatorTool                     : Acrobat PDFMaker 23 for Word
CreatorTool                     : Acrobat PDFMaker 7.0.7 for Word
CreatorTool                     : Acrobat PDFMaker 9.0 for Word
Producer                        : Acrobat Distiller 6.0 (Windows)
Producer                        : Acrobat Distiller 7.0.5 (Windows)
Producer                        : Acrobat Distiller 8.2.3 (Windows)
Producer                        : Adobe PDF Library 11.0
Producer                        : Adobe PDF Library 15.0
Producer                        : Adobe PDF Library 20.6.74
Producer                        : Adobe PDF Library 21.5.92
Producer                        : Adobe PDF Library 23.6.156
Producer                        : Adobe PDF Library 9.0
As to the relevance, it looks like the only way you can find out anything beyond the name would be to ask Adobe, and it's unlikely that they would answer.

[Phil Harvey]

I'll add the ability to read/write this tag in PDF and XMP-pdfx in version 13.19.

But I don't know what this tag is for.

- Phil

[BitWyse]

Thank you both for the quick reply and opinions shared.

@StarGeek In my case the creator tool is also "Acrobat PDFMaker 23 for Word". It is interesting that in such a pool of documents a small percentage have the tag.

The hunt shall go on.