I was ticketed for "improper parking" at Avalon in February. My left wheels were slightly over the imaginary line that marks the alley lane. 7/8ths of the vehicle was behind the concrete stop.A car actually parked in the alley did not get ticketed because I emerged from the store and the meter maid literally ran to her vehicle and skidded away. I would be happy to attach the photo I took to demonstrate exactly how absurd that ticket was - but I can't figure the attachment.
So it is my personal experience that they are ticketing legally parked people. Now I hear that they are going to be ticketing on residential streets - maybe your wheel is too far over onto some arbitrary demarcation and so they will use the catch-all "improper."