PDF keywords

[brabo]

I want to populate the Title, Author, Subject, and Keywords fields in a PDF. These fields are all empty in the target file (see Before.png and TheRoadNotTaken.pdf). I'm using the following command:

exiftool -Title="The Road Not Taken" -Author="Robert Frost" -Subject="Famous Poems: The Road Not Taken by Robert Frost" -sep ", " -Keywords="road, Robert Frost, famous poems, poetry" TheRoadNotTaken.pdf

In the resulting file (see After.png and TheRoadNotTaken - After ExifTool.pdf), the Title, Author, and Subject are populated correctly but Keywords is populated incorrectly as per my expectation:

1. There shouldn't be quotation marks.
2. The part after the second quotation mark -- ; Famous Poems: The Road Not Taken by Robert Frost -- shouldn't be there (it appears to have been copied from Subject.
3. The 4 keywords should be considered to be individual keywords, not one long concatenated keyword.

Can anyone please help?

[greybeard]

Looks OK to me

I just ran the following command on MacOS

Code Select Expand

exiftool -Title -Author -Subject -Keywords -sep "//" 'TheRoadNotTaken - After ExifTool.pdf'
and got this output

Code Select Expand

Title                          : The Road Not Taken
Author                         : Robert Frost
Subject                        : Famous Poems: The Road Not Taken by Robert Frost
Keywords                       : road//Robert Frost//famous poems//poetry


[brabo]

Thanks for checking. I'm using a Windows 10 PC and am seeing the incorrect results in Adobe Acrobat Reader v2022 by clicking on File -> Properties.

[greybeard]

Thanks for checking. I'm using a Windows 10 PC and am seeing the incorrect results in Adobe Acrobat Reader v2022 by clicking on File -> Properties.

Are you sure thats not just the way Acrobat shows properties? I tried a couple of other programs (Chrome and Mac Preview) and they show what you would expect.

[brabo]

I have multiple PDFs that show a simple list of words and phrases separated by commas in the Keywords field in Reader; they don't include quotation marks and don't repeat the content of the Subject field.

But I did not create those PDFs so don't know how those fields were populated. Also I haven't used ExifTool on those files; I received them with all the metadata already populated.

So I'm assuming that those are examples of how Acrobat typically displays keywords.

[brabo]

I just found this screenshot online as an example.

[Hubert]

Writing the tag -xmp-pdf:subject (as opposed to just -subject) prevents the Subject field being duplicated in the Keywords field in Acrobat Reader.

I haven't (yet) discovered a way of removing the enclosing double quotes in Acrobat Reader. In Preview on macOS they are displayed like this:

[brabo]

Thank you! That solves a big part of the problem!

[brabo]

If anyone knows how to get rid of the quotation marks in the Keywords field, please let me know. Thanks!

exiftool -Title="The Road Not Taken" -Author="Robert Frost" -xmp-pdf:Subject="Famous Poems: The Road Not Taken by Robert Frost" -sep ", " -Keywords="road, Robert Frost, famous poems, poetry" TheRoadNotTaken.pdf

[greybeard]

If anyone knows how to get rid of the quotation marks in the Keywords field, please let me know. Thanks!

exiftool -Title="The Road Not Taken" -Author="Robert Frost" -xmp-pdf:Subject="Famous Poems: The Road Not Taken by Robert Frost" -sep ", " -Keywords="road, Robert Frost, famous poems, poetry" TheRoadNotTaken.pdf

Maybe this is a question for the Adobe forum - the quotes are not physically in the file so its the way that Adobe chooses to display the keywords

[StarGeek]

You should take note that there are several PDF tags that have conflicting uses and setup.  There are PDF specifc tags and then there are XMP PDF tags.  And there is some conflict between those tags and the more common Dublin Core XMP tags, which are often in PDFs as well.

For example, Subject is a list type tag often used keywords and can appear in PDFs. But PDF:Subject and XMP-pdf:Subject are strings, with the latter marked as Avoid, so you have to explicitly use XMP-pdf:Subject to set it.

The PDF:Keywords is a list type tag, but XMP-pdf:Keywords is a string.

This basically comes down to a FAQ #3.  Find a file that has the data in the right places, or if you have a program that writes the data, use that to write unique values to all the tags you want to use.  Then use the command in FAQ #3 to figure out what are the actual tags you want to use.