A PDF is a container.
You need to see which URL a page declares as its canonical version.
Website & SEO
Check which URL this page says is the real one.
Find the rel=canonical tag, resolve relative URLs and flag missing or multiple canonical declarations.
Useful to know
Four things worth knowing.
Opening is not the same as correct.
A canonical is a strong hint, not a redirect or an absolute command to search engines.
Check the changed pages.
Watch for missing, duplicate, relative or accidentally cross-domain canonicals.
Keep the source document.
For a normal unique page, a clean self-referencing canonical is usually the simplest setup.