I want to contact my local city hall and ask for permission to use some of their public data. I ordered a map with all the addresses and housenumbers for my town, for free. I asked about license, but got no response. (Probably didn't know what I was talking about) I realize I need to ask the person in charge of information. But what is it they need to do? "Release it under the CC-BY-SA", what is that in real terms? Put it on their website with the CC-BY-SA logo? That might be a hassle for them. Can they send it to me with the logo? Can they just say to me it is OK to use? Is there a straightforward way of getting this done?

I want to contact my local city hall and ask for permission to use some of their public data. I ordered a map with all the addresses and housenumbers for my town, for free. I asked about license, but got no response. (Probably didn't know what I was talking about) I realize I need to ask the person in charge of information. But what is it they need to do? "Release it under the CC-BY-SA", what is that in real terms? Put it on their website with the CC-BY-SA logo? That might be a hassle for them. Can they send it to me with the logo? Can they just say to me it is OK to use? Is there a straightforward way of getting this done?