A more thorough explanation:

The legal-acumen doctrine is a principle in law that allows equity to be invoked to remove a defect or invalidity in a claim to land that cannot be discovered without legal expertise.

For example, if a person purchases a piece of land and later discovers that there is a defect in the title that was not apparent at the time of purchase, the legal-acumen doctrine may be used to remove the defect. This is because the defect could not have been discovered without legal expertise.

Another example is if a person inherits land from a relative and later discovers that there is an invalidity in the claim to the land. Again, the legal-acumen doctrine may be used to remove the invalidity.

These examples illustrate how the legal-acumen doctrine can be used to ensure that a claim to land is valid and free from defects, even if those defects are not immediately apparent to the average person.