How to check if a PDF is a PDF/A

[aborruso]

Hello,
I have a PDF/A file, and if I run "exiftool input.pdf" I have the output below.
It's a PDF/A created using libreoffice.

How can I read that this is a PDF/A?

Thank you very much

ExifTool Version Number         : 12.16
File Name                       : tmp.pdf
Directory                       : .
File Size                       : 15 KiB
File Modification Date/Time     : 2022:08:31 16:24:11+02:00
File Access Date/Time           : 2022:08:31 16:24:12+02:00
File Inode Change Date/Time     : 2022:08:31 16:24:11+02:00
File Permissions                : rwxr--r--
File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.6
Linearized                      : No
Page Count                      : 1
Page Layout                     : SinglePage
Language                        : it-IT
Tagged PDF                      : Yes
Part                            : 3
Conformance                     : B
Producer                        : LibreOffice 7.3
Creator Tool                    : Writer
Create Date                     : 2022:08:31 16:24:11+02:00
Creator                         : Writer

[StarGeek]

What do you mean by "read that this is a PDF/A"?  Do you mean that you want exiftool to check if it qualifies as a PDF/A?

I think that is a bit beyond the scope of exiftool, as reading the Wikipedia description seems to indicate that a lot of checks and verification needs to be done to make sure all the data is embedded and nothing is pulled from an external source.

This StackOverflow question seems to give some options for detecting if a PDF is compliant.