A more thorough explanation:

Definition: In facto proprio is a Latin term that means "concerning one's own act."

Example: A judge may issue a ruling in facto proprio, meaning that the decision was made based on their own authority and not influenced by outside factors.

Explanation: In facto proprio is often used in legal contexts to indicate that a decision or action was taken by an individual based on their own authority or initiative, rather than being influenced by external factors. In the example given, the judge's ruling was made solely based on their own interpretation of the law and the facts presented in the case, without being swayed by any outside pressures or influences.