"There is only one person in charge of trademark filing" means that in the process of trademark filing, each trademark can only designate one person in charge. This person in charge is responsible for the whole process of trademark application and filing, including the preparation, submission and follow-up of application documents, as well as communication with the Trademark Office and handling related affairs. This regulation of the person in charge helps to ensure the consistency and efficiency of trademark filing and reduce potential confusion and contradictions. Only one person in charge can provide clear responsibilities and decisions to improve the management efficiency of trademark filing process. In addition, only one person in charge can help ensure communication and coordination in the filing process and avoid inconsistent or conflicting information. Therefore, "there is only one person in charge of trademark filing" is a regulation in the process of trademark filing, aiming at ensuring the standardization and efficiency of the filing procedure.