Negotiable Instruments Act Article 59

A guaranty shall be made in writing on the bill, or on a duplicate of the bill, stating the following items, and shall be signed by the guarantor or guarantors:1. An expression of intent by the guarantor or guarantors to act as such.2. Name of the person guaranteed.3. Year, month, and date.If a guaranty is undated, the date of drawing of the bill shall be the date of guaranty.
中文原文 票據法第59條
保證應在匯票或其謄本上記載左列各款,由保證人簽名。
一、保證人之意旨。
二、被保證人姓名。
三、年、月、日。
保證未載明年、月、日者,以發票年、月、日為年、月、日。

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