Yes, laws vary by jurisdiction. Nonetheless, we have a lot of licences which work as worldwide as possible. As much as I wish otherwise, it does not appear to

Yes, laws vary by jurisdiction. Nonetheless, we have a lot of licences which work as worldwide as possible. As much as I wish otherwise, it does not appear to be possible to dedicate works to the public domain in Germany, and quite possibly other jurisdictions. As such, it's best to offer an MIT-style licence for residents of such jurisdictions. This doesn't stop you making a public domain declaration in jurisdictions where you can.