The City Of Ann Arbor - Government issued the following announcement on Dec. 1.
Beginning December 1, the free, 15-minute curbside carryout parking spaces in downtown Ann Arbor will be designated by a RED meter bag indicating “No Parking 15 Minute Loading/Unloading.” The change is necessary to preserve these spaces for the intended purpose of free, short-term parking to support the curbside carry out service many restaurants and retailers are relying on. The new bags enable Community Standards officers to enforce the 15-minute parking limit and issue tickets to those using the spaces for long term parking.
Original source can be found here.
Source: The City Of Ann Arbor - Government