A more thorough explanation:

DE LIBERTATE PROBANDA

De libertate probanda is a Latin term used in law which means "for proving liberty". It refers to a writ that was issued to a sheriff to protect a person who was accused of being a villein (a feudal tenant who was legally tied to a lord's land) from harassment until their status was determined by the justices of assize. The writ directed the sheriff to take security from the accused person and ensure their safety.

For example, if a person was accused of being a villein, they could request a de libertate probanda writ to protect themselves from harassment while their status was being determined. The writ would require the sheriff to take security from the accused person and ensure their safety until the justices of assize made a decision.

Another example could be a person who was wrongfully imprisoned and claimed to be a free person. They could request a de libertate probanda writ to prove their liberty and protect themselves from further imprisonment or mistreatment.

These examples illustrate how the de libertate probanda writ was used to protect individuals from harassment and ensure their liberty was proven before any further actions were taken against them.