Regulations Governing the Handling of Mail Article 27
“Express mail” refers to mail items sent between designated domestic areas or with the agreement of a foreign postal administration between the R.O.C. and designated post office branches in the said nation, or with the private sector companies providing EMS service in the country of destination so as to be delivered to the addressee as fast as possible and within an agreed-upon time limit..
中文原文 郵件處理規則第27條
郵件在國內指定之地區間互寄或經外國郵政機構同意與其指定之郵局間互寄，或交由在寄達國提供遞送服務之民營公司，以最快速方法優先處理，並在約定之時間內送達收件人者，為快捷郵件。