Enforcement Rules of the Negotiable Instruments Act Article 8

A form may be printed on the back of a negotiable instrument or on an allonge annexed to the instrument for an endorser to write on, but endorsement may not be made on an allonge unless no space is available for endorsement on the back of the instrument.
中文原文 票據法施行細則第8條
票據得於其背面或黏單上加印格式,以供背書人填寫。
但背書非於票背已無背書地位時,不得於黏單上為之。

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