Tenn. Code Ann. § 6-54-506

Any municipality that has before March 16, 1951, enacted a code or public record by reference thereto shall not be required to reenact such code or public record by reason of this part, and all previous incorporations by reference that would have been valid if this part had then been in effect are hereby ratified and declared effective; provided, that a copy was forthwith filed with the clerk or recorder of the municipality, if it had not already been filed.