Disclosed is a non-transitory storage medium storing a communication program for causing a processor to execute a method including steps of receiving an input of facsimile data; determining whether an identification image is added to the received facsimile data; a step of retrieving, when the identification image is added, information indicating an association with different facsimile data from the identification image that is added to the facsimile data; storing the received facsimile data in a predetermined memory, wherein the received facsimile data is associated with the different facsimile data based on the retrieved information; generating, when the identification image is not added, the information indicating the association with the different facsimile data; and adding, to the facsimile data, the identification image that is generated based on the information indicating the association with the different facsimile data.