Tennessee Return of Service form Instructions is a set of instructions to be used in completing the Tennessee Return of Service Form. The Return of Service Form is a document used to report service of process, which is the delivery of a legal document, such as a summons or subpoena, to a party in a legal case. The document is then returned to the court in order to acknowledge that the defendant was served. There are two types of Tennessee Return of Service Form Instructions: Instructions for Service by Mail and Instructions for Service by Personal Delivery. Instructions for Service by Mail: This set of instructions must be followed when serving process by mail. The form must be completed and sent to the defendant via certified mail. The defendant must then sign the form and return it to the court. Instructions for Service by Personal Delivery: This set of instructions must be followed when process is served in person. The form must be completed and given to the defendant in person. The defendant must then sign the form and return it to the court.