The parol evidence rule: 1)

states that any spoken or written words that are in conflict with what the written contract states should be introduced as evidence in a court of law.

2)

refers to supplementary evidence or conditions to be added to an existing written contract.

3)

specifies that certain kinds of agreements must be in writing to be enforceable.

4)

does not prohibit a person from legally entering into oral contracts for certain kinds of agreements.