Wikipedia

I had a parking chair out in front of my apartment. Someone threw it on the sidewalk and put their car into the spot I'd spent hours clearing (lotsa heavy, icy, snow plowed up into the driver's side..) When I got back from the grocery store, I was pissed off, so I dropped my food into the hallway of the apartment, drove around until I found a spot in the nearby municipal lot then came home and shoveled ALL the snow right back into the space around the car. Needless to say, when the driver got back after they'd been doing whatever.. (likely drinking, the time he returned was about right for last call) he was not happy. I heard a lot of cussing and stomping.

Legalities aside, If I clear a space and it takes me a long time.. Oh no buddy.. I'm putting ALL the snow back.

You want the space.. YOU shovel it open.

for example, in Chicago, where it is referred to as "dibs"

I'm from the northeast but where I'm from dibs can be called on anything, not just a parking spot. Parking chairs are dibs with physical objects. Dibs is used when you want your chair back after leaving the room, you call dibs as you get up so no one will steal your chair.

Kind of a tangent, but the tailend of college I shared a house with four other guys, which meant street parking in a college neighborhood where the streets were often mostly full. Our next door neighbor had a car and a half length of curb between him and the next house, and once asked me to park a little further back to leave space for his trash can so he could use his driveway without being blocked by his trash can. It just so happened trash day was Monday and I delivered Amazon packages through the post office Sundays, so I often got off work at a time other folk were away from home and the space in front of his house was open. I always felt pretty good pulling in to maximize space for his bin, effectively reserving the space for him.