Signing a waiver indicates that you are giving up certain rights that may be contractually granted to you. An example of a waiver would be foregoing your legal rights in the event of a foreclosure. Waivers can also be used by lenders and other agents to protect themselves against lawsuits and other claims. Always read carefully before signing any sort of waiver. These are legal documents that will be accepted in a court of law should a dispute arise. The only time a waiver is invalid is if it is signed under duress or it otherwise violates the law. For example, a waiver could not be signed that says a tenant is not able to recoup their security deposit. State law would trump that in the majority of cases.