Mo. Rev. Stat. § 532.110: Writ not to be disobeyed — how endorsed.

Such writs shall not be disobeyed for any defect of form; and anyone who shall be served therewith shall be deemed to be the person to whom it is directed, although it may be directed to him by a wrong name or description, or to another person; and to the end that no person may pretend ignorance therein, every writ of habeas corpus, issued under the provisions of this chapter, shall be endorsed with these words: "By the habeas corpus act".