Enforcement Rules of the Government Procurement Act Article 29

The term "in writing and sealed" referred to in paragraph 1 of Article 33 of the Act means packing the tender in an opaque envelope or container and sealing it with paste, glue, tape, staple, rope, or other similar materials.The name and address of the tenderer shall be indicated on the envelope or container, and the tenderer shall have its own choice on the place of mailing.The term “designated place” referred to in paragraph 1 of Article 33 of the Act shall not be confined to the post office box number of an entity as the only place of receiving tenders.
中文原文 政府採購法施行細則第29條
本法第三十三條第一項所稱書面密封,指將投標文件置於不透明之信封或容器內,並以漿糊、膠水、膠帶、釘書針、繩索或其他類似材料封裝者。
信封上或容器外應標示廠商名稱及地址。
其交寄或付郵所在地,機關不得予以限制。
本法第三十三條第一項所稱指定之場所,不得以郵政信箱為唯一場所。

English translation for reference only; the Chinese text prevails. Not legal advice.