A more thorough explanation:

An interlineation is when new language is added in between the lines of an existing legal document. This is usually done to clarify something or to add something that was forgotten. When an interlineation is made, the document is legally changed. All parties involved usually initial the change or the document is retyped and then signed.

Example 1: A contract is written between two parties for the sale of a car. The contract states that the car is red, but upon inspection, the car is actually blue. The parties can make an interlineation to change the color of the car from red to blue.

Example 2: A will is written leaving all assets to one child, but the writer later decides to leave some assets to another child as well. An interlineation can be made to add the second child to the will.

These examples illustrate how an interlineation can be used to make changes to a legal document after it has been written. It is important to make sure all parties agree to the change and initial it to ensure it is legally binding.