Parking signs usually show the number of free parking spaces, short messages (FREE, FULL...) or guiding arrows. They can be easily integrated into any parking system using some of the most common communication protocols (UTMC, Modbus, NTCIP, Profibus...) or the DMV Oblak protocol. There is also the possibility of integration in such a way that the software of the parking system forwards the data to the DMV software, which then displays them on the parking signs - the DMV Parking Guidance System.