A more thorough explanation:

Definition: Omissa et male appretiata is a term used in Law Latin that refers to things that have been omitted and erroneously valued. For example, when an executor confirms and omits part of the deceased's assets in the inventory, they may have the mistake corrected. If they do not take steps to correct the mistake, anyone interested in the succession may apply to have the executor compelled to confirm the omission or confirm it themselves. Ordinary executors ad omissa et male appretiata should call the principal executor to their confirmation, or it will be null. However, this rule does not apply to executors-creditors.

Example: John is the executor of his late father's estate. He creates an inventory of his father's assets but accidentally omits a valuable painting. John's sister, who is also an heir to the estate, notices the omission and requests that John correct the mistake. If John does not take steps to correct the mistake, his sister can apply to have him compelled to confirm the omission or confirm it herself.

Explanation: This example illustrates how omissa et male appretiata applies to the situation where an executor omits part of the deceased's assets in the inventory. In this case, John omitted a valuable painting, which is an example of something that has been omitted. His sister, who is interested in the succession, can apply to have the omission corrected if John does not take steps to do so himself.