When a subdivider leaves a little sliver of land between the land they subdivided and its new streets and an adjacent property, which makes makes access to the new public street impossible because they can't access the street without the permission of the owner of the "spite strip".
Usually done when the subdivider couldn't get the neighbors property, so in spite, reduces the developability of the neighbor's land.
That's the type of the situation I'm most familiar with.
I'm sorry. Is my bias showing?