A more thorough explanation:

Definition: Ad perpetuam remanentiam (ad pər-pet-yoo-əm ri-man-en-shee-əm) is a Latin legal term that means "to remain forever."

Example: When a vassal surrendered the right of property to the superior ad perpetuam remanentiam, the surrender was in favor of the superior. This is different from a transfer in favorem, in which the vassal transferred the property to the superior to be regranted in favor of a purchaser.

Explanation: The example illustrates how ad perpetuam remanentiam is used in a legal context. When a vassal surrenders their right of property to a superior ad perpetuam remanentiam, it means that the property will remain with the superior forever. This is different from a transfer in favorem, where the property is transferred to the superior to be regranted to a purchaser.