What a duplicate title actually is
A duplicate title is a replacement Certificate of Title when the paper is lost, stolen, or mutilated. The new sheet cancels the old one. It is not salvage and not the registration.
Is a duplicate title a salvage brand? No. People also treat it like the glovebox registration card. Those are different papers.
A duplicate — replacement title — is a new Certificate of Title the office prints when the paper is lost, stolen, or mutilated. Issuing it cancels the old sheet. California prints that on REG 227: Application for Replacement or Transfer of Title. You can ask for a replacement only, or for a transfer when the title is missing. Section 3 carries the warning: the replacement cancels the original. Section 5 is the lienholder release — notarized. An ordinary owner duplicate often is not.

Florida is HSMV 82101: Application for Duplicate or Lost in Transit / Reassignment. Lost, stolen, damaged, lost in transit, or a duplicate with a transfer. That is still a title application. It is not the registration card. It is not a salvage stamp. The clerk wants the ownership sheet back in the file. This is the form that asks for a new one.
