Adding Custom Properties in PDF

The axf:document-info extension has the option to specify an xmp file which can declare custom properties. Refer to and custom-property.xmp. The custom data would then use the ‘pdfx' adobe extensions:

---- custom-property.xmp ----

<rdf: ...>
<pdfx:CustomData>my custom data</pdfx:CustomData>

---- ----

<axf:document-info name="xmp" value="custom-property.xmp" />

ahfcmd -d -o sample.pdf -x 4

Note: These values will not be displayed in the Acrobat ‘properties' gui but should be available to pdf scanning software that relies on xmp metadata.