The numbers are the available free spaces on that floor so that you know if you need to go higher or direct drivers to the empty sides. The reserved spots are for the business and shops, these are usually part of the 2nd/3rd floor. If the spot doesn't say reserved, it's free to use
I'm sure it's to tell you which spot you parked in for easy reference
Some of the reserved spots are available after normal business hours or on the weekends. Just read the signage closely.
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