Microsoft had what they called &quot;placeholders&quot; and it worked great, but it did confuse some users who looked for a file, saw it was &quot;there&quot; and happily went offline. Only to find it was only a placeholder. Furthermore, on devices with limited storage (phones, tablets) even the small size of the placeholders becomes a problem when the number of files is big enough. So Microsoft temporarily removed the placeholders functionality, promising to bring it back in the near future using some new (at the time not yet invented?) technique that would solve the problem.