A more thorough explanation:

quae est eadem

Quae est eadem is a Latin phrase that means "which is the same." In the past, it was used in legal cases where a defendant argued that their actions were justified because they were the same as those alleged by the plaintiff. For example, if a plaintiff accused a defendant of trespassing on their property, the defendant could argue that they had permission to enter the property, and therefore their actions were the same as those alleged by the plaintiff.

Imagine that a person owns a piece of land and gives their neighbor permission to cross it to get to their own property. However, the neighbor starts using the land for other purposes without permission. The landowner could sue the neighbor for trespassing. If the neighbor argues that they had permission to enter the land, they could use the phrase "quae est eadem" to show that their actions were the same as those alleged by the landowner.