Over time, Microsoft also plans to address the complaints that arose late last year when it announced it was discontinuing the beloved Windows 8.1 version of the sync experience which, unique among all OneDrive sync clients, lets you browse offline-only files in addition to files you’ve synced to the PC. (And do so while the PC is offline.) No, Microsoft isn’t bringing back placeholder files. But it has a plan to sort of approximate placeholder files.
It’s called offline files. It will debut first in the mobile clients for Android and iOS in Q3 2015, giving us a decent idea of how this feature will look and work in Windows 10 (and on Mac). As I understand it, you will be able to browse through your offline-only files in a read-only, and only when you’re online. Then you can use the selective sync mechanism to mark files and folder for offline sync.