Ohio Rev. Code § 5309.18
Any person who claims an interest in, or who may be affected by the judgment in a land registration case, whether or not named in the notice required by section 5309.15 of the Revised Code, may appear and file an answer or other pleas on or before the answer day, or within such further time as the probate court or the court of common pleas allows. Such answer shall state all objections to the application, shall set forth the interest claimed by the person who files it, and shall be signed and sworn to by him or by a person in his behalf . Any person claiming an interest in the land may by answer or other plea oppose the application for registration of the land as belonging to the plaintiff, or may by cross-petition set up a demand to have the title claimed by the plaintiff registered in the name of the cross-petitioner. If a person answering claims an interest in, or lien upon the property separate from that claimed by the plaintiff, such person may ask to have his title to such interest or lien registered.
R.C. §5309.18