When uploading a PDF file that contains embedded highlights and comments (annotations), the AI is unable to detect or extract them. Instead, it reports that it can only access the plain text layer of the file.

To confirm that the annotations were properly embedded, I uploaded the exact same PDF document to ChatGPT, which was able to fully read and enumerate all of the highlights and comments correctly.

This functionality is critically important, especially when evaluating engineering reports, where highlights and comments often contain direct critiques, technical clarifications, or challenges to the engineer’s findings.