That legal status was clarified only in the 1980s. Previously, the conduct of repo had been remarkably informal: there was no clearly established legal definition of "repo." Sometimes "two parties will do a repo but sign no agreement; they may be just sloppy, but more likely, party A's lawyer doesn't like party B's agreement and vice versa" (Stigum 1989, p. 5, emphasis in original).

Donald MacKenzie, An Engine, Not a Camera, loc. 1294