I’ve sent you some samples privately. Thanks for looking into this.

I can consistently created these in MS Word when choosing Enable Accessibility and Reflow.

We are also finding these hidden layers being generated by other applications as well.

Sebastian, it is my understanding that PDF/A doesn’t permit layers, so valid PDF/A files would not contain them.

Carl

I just tried this with Word 2003 and did NOT get any layers (hidden or otherwise) in my PDF.

I then tried Excel 2003 and again, no layers (hidden or otherwise).

With PowerPoint, I was asked about turning speakers note to text annotations ON A SEPARATE LAYER - but I chose not to do that. However, it did create a VISIBLE layer called background (as noted by Sebastian).

If you are seeing a hidden layer, please send me a sample PDF.

Leonard

I had come across this issue too and your blog now prompted me to have a brief look into it.
The hidden layer generated by PDFMaker from MSPowerPoint is named ‘Background’ and contains the background elements form the ‘Master’ in the ppt. Apparently this hidden layer (OCG) is set to be visible and printable and thus is treated correctly if we’re flattening the laysers and nothing gets lost.
IMHO this is a ‘hidden feature’ build into ealier versions of PDFMaker which now in Acrobat8 has been turned into an actual ‘new’ feature. As one uses PDFMaker in ppt with Acro8 the ‘Background’ layer is generated and displayed in the layers pallette, With this it’s possible to interactively switch it on and off for viewing and printing.
If one genrates PDF/As though this ‘feature’ is switsched off and the resulting PDF does not have layers.

Regards
Sebastian