Regulations of the Land Registration Article 96

In the case that multiple parties jointly own the same single exclusively owned part of strata titled improvement and some of the said parties wish to dispose, change, or create obligation on the exclusively owned part and the proportionate shares of the associated improvement right by exercising Article 34-1 of the Land Act, the joint owner of the improvement shall signify all of the joint owners of such exclusively owned part, and the proportionate shares of the right of the improvement shall signify the proportionate shares of the exclusively owned part jointly owned by all joint owners.
中文原文 土地登記規則第96條
區分所有建物,數人共有一專有部分,部分共有人依土地法第三十四條之一規定就該專有部分連同其基地權利之應有部分為處分、變更或設定負擔時,其基地共有人,指該專有部分之全體共有人;其基地權利之應有部分,指該專有部分之全體共有人所持有之基地權利應有部分。

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