The Metadata Most People Never Check
Every PDF carries a metadata block — Title, Author, Subject, Keywords, Creator, and Producer — separate from its visible page content, and it's easy to forget this exists since none of it displays when you open and read the document normally. This metadata frequently reveals more than intended: the real author's name (not necessarily who's credited in the visible document), which software generated the file (sometimes revealing internal tooling or licensing details), and edit history details that can persist through visible-content redaction if only the page content, not the metadata, was cleaned up.
Editing this metadata directly — correcting an inherited "Author" field left over from a template, removing a Creator field that references internal software, or simply clearing fields before sharing a document externally — is a distinct operation from anything that touches the visible page content, which is exactly why "cleaning" a document's visible text alone doesn't guarantee its metadata is equally clean.
Checking and adjusting PDF metadata before sharing anything externally is a quick, easy-to-skip step that's specifically worth doing for contracts, reports, or any document where the metadata's origin details (internal software names, unintended author attribution) shouldn't be part of what an external recipient sees.