Even today, Google Drive isn't strictly hierarchical, in that a file can still be in multiple folders / locations. They have, however, made it awfully hard to d

Even today, Google Drive isn't strictly hierarchical, in that a file can still be in multiple folders / locations. They have, however, made it awfully hard to discover. If you have an existing item or items selected, you can "add" them to a different folder by hitting Shift+Z; I don't think this exists in any menu. It is in the list of keyboard shortcuts (hit "?"). These feel sort of closer to some form of link than a tag, though.