It depends on state law. Most states view mobile homes as vehicles and issue titles. Some states allow the home owner to file a form indicating that the mobile home has "lost its mobility" & will then declare it real property. The main difference is whether you pay car tax or property tax on the home, and whether a bank will finance it at mortgage rates. Visit your county courthouse and talk to the assessor, recorder, & vehicle licensing departments.
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This is not legal advice and you are not my client. Double check everything with your own attorney and your state's laws.