That is a great change to the papers of the past where you have to have an affiliation to a university to get access to a paper and sometimes even that is not enough.
‘Oxford Scholarship Online’ would license different sets of books to different departments; so someone from the philosophy department couldn’t get access to books classified under sociology or history.
Imagine doing something similar at the checkout table in a ‘physical’ library.
A pedantic thing to say, surely, but the title really should’ve been: “Linux Directory Structure” – ‘Linux filesystems’ (the title in the graphic) refers to a different topic entirely; the title of this post mitigates the confusion a bit, though still, ‘directory structure’ is the better term.