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.
To be safe, if it’s in front of a house, I always vote to reject it. Most of the time the submitter has no way to prove that it is not private property other than typing what basically amounts to “trust me, bro.” Sorry, but when it comes to placing a Wayspot in front of someone’s house (an issue that was such a big deal it became a class action lawsuit in the US in 2016), I’m going to err on the side of caution. In fact, the ruling in that case told us that anything within 40 m of SFPRP needed to be judged with extra scrutiny. Therefore, my best judgment is that single family private homes should not have wayspots right in their front yards.
Never mind! Despite my specifying that these were clearly not applicable properties (apartments and hotels) and clearly eligible items (swimming pools) you all derailed the topic into debating single family property and questionable spots like trail markers and libraries…. and exactly where property lines are… and in the meantime have actually ignored the entire point.
Apologies that you feel this was derailed. I thought it was a great conversation starter for clarification of private property. I did agree with you that the review flow should indicate this in my first comment. And I also thought that good questions came up for a post in Review Support that is titled: Clarification on “private property”
In the future, you can flag any comments that wander off your intended subject matter as being off topic. What I would recommend doing is making a post in Bug Reports & Technical Support explaining that the “private property” rejection reason is misleading and needs to be fixed.