The status bar is the phone/tablet equivalent to the menu bar on PC. It displays a variety of things you may need to see at a glance (always-present items in bold):
To maximize consistency of position, they should be present in this order, with consistent spacing, such that the current time is always at the trailing end.
On a technical level each of these is an instance of an indicator.
The interactions for browsing, opening, and closing indicator menus are described in “Indicators - RTM Usability Fix” (Canonical-only link).
The Rotation Lock indicator is defined here because it is too simple to need its own specification.
Whenever Rotation Lock is on, the display orientation should become fixed to its current setting.
The “Rotation Lock” switch is always present in the System Settings quick-access area, as well as being accessible from the indicator when Rotation Lock is on.
Whenever there is not enough room to show all indicators beside the in-app search “SEARCH” label, as many as necessary on the leading side should be hidden.
Whenever you interact with the indicators at all, or whenever there is not enough room to show them all beside “SEARCH” and a new indicator appears, the “SEARCH” label and icon should temporarily fade out, leaving all the indicators visible. When the search label and icon fade back in, they should once again cover as many indicators as necessary on the leading side.
On a display 40 grid units wide, there should never be a situation where indicators are not visible even with the search label and icon removed. If this happens, it is a bug, which might be solved by narrowing an indicator or by abolishing it altogether.