Can my neighbor reserve space outside their house?

I tried to find a parking space around Richmond district in San Francisco at night, I spotted one close to my home, but the homeowner came down and told me the space in front of his home is reserved, it can't be parked except by him. He pointed out the white number mark(his house number) on the curb is the evidence that the city grants him this space because he paid...is this true? he said will call towing company if I park my car in front of his home...unbelievable..