There is a clarification on these, but it is still a murky area.
In the US, if the Little Free Library is between the sidewalk and the street, they are usually accepted, but the submitter should show that this is public property where they are submitting. The laws vary different places.
If the LFL is between the sidewalk and the house, then that is usually SFPRP (single family private residential property) and should be rejected, even if there is a fence between the house and the sidewalk and the LFL is mounted on the fence.
If there is no sidewalk, then the SFPRP property usually extends to the road unless the submitter demonstrates otherwise.