If an unauthorized car is parking in your reserved spot, YOU, the unit owner can have it ticked and/or towed.

From the city: city.milwaukee.gov/Parking/Service-Requests/Private-Parking

For an unauthorized vehicle you would like removed from property you lease or own:

Call 286-CITY (2489) for parking enforcement assistance.

You will need to download and complete an “Application for Citation, Placard, or Tow on Private Property” to give to the Parking Enforcement Officer upon arrival to issue the citation. The Parking Enforcement Officer will have blank forms available for you to complete. You will also need a valid state-issued driver’s license or identification card, City of Milwaukee municipal ID card, military ID, or a passport and be present when the Parking Enforcement Officer arrives.

Here is a copy of the application with the areas to be filled in highlighted.

To access this, right click on the top right "pop-out" square and then download or print.