From Metadata

Suppose while enumerating, we found some PDF files from the website. We can check for information available in metadata.

For this purpose, we can use exiftool.

exiftool(1): Read/write meta info in files - Linux man pagelinux.die.net

For more details

Common use case:

exiftool -duplicates -unknown $FileName
exiftool -a -u $FileName

-a or -duplicates : to display duplicated tags

-u or -unknown to display unknown tags.