A more thorough explanation:

IN POSSESSORIO

In possessorio (in pah-ses-sor-ee-oh) is a legal term that refers to a possessory suit.

When someone is in possessorio, it means they are involved in a legal dispute over possession of a property or object. This type of lawsuit is typically brought by someone who is currently in possession of the property or object, but is being challenged by another party who claims to have a right to it.

An example of a case in possessorio would be if two neighbors were fighting over a strip of land between their properties. If one neighbor had been using the land for years, but the other neighbor suddenly claimed ownership and tried to take it away, the first neighbor could file a lawsuit in possessorio to protect their right to continue using the land.