Tt's possible for a PDF to be annotated with the original Unicode text (look up the `/ActualText` feature in the spec), to support extraction of the underlying

Tt's possible for a PDF to be annotated with the original Unicode text (look up the `/ActualText` feature in the spec), to support extraction of the underlying text rather than the shaped glyph stream for purposes such as copy/paste and search. However, few PDF generators do this, and not all PDF readers have good support for it. So results vary depending on the specific tools and use-case.