Enforcement Rules of the Detention Act Article 43

When a detained defendant held incommunicado by ruling of the court sends a document other than letters in accordance with Paragraph 6, Article 66 of the Act, the detention center shall, pursuant to Paragraph 3 and Paragraph 4, Article 105 of the Code of Criminal Procedure, prepare and submit relevant data to the public prosecutor in the stage of investigation or to the court in the stage of trial for consent before permitting the document to be sent.
中文原文 羈押法施行細則第43條
經法院裁定禁止通信之羈押被告,依本法第六十六條第六項規定發送書信以外之文件時,看守所應檢具相關資料依刑事訴訟法第一百零五條第三項、第四項規定,偵查中報請檢察官、審判中報請法院同意後,始得發送。

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