Significant Characteristics When preservation actions are performed on a digital object in its original environment, usually a new digital object is created which is rendered or executed in a new environment. For example, a Word file in its Microsoft rendering environment is migrated to a PDF file in an Adobe rendering environment. With most preservation actions,
there is a risk that some characteristics of the original digital object will be lost or modified. In the example migration, one might lose original macros, editing histories, and a degree of interactivity not supported in PDF. Significant characteristics reflect business requirements. They capture the characteristics of the original object and environment that need to be preserved by a preservation action. For example, one might wish to specify that for a newspaper collection all pages need to maintain their original margins in a content migration. This requirement guides decisions on which preservation actions should be selected. This specific requirement would, for example, exclude migrations which include cropping within the page edges. Significant characteristics are a form of preservation metadata that has recently found increased attention. PREMIS supports the capture of simple significant properties for individual digital objects; the PRONOM file format registry project is working on identifying properties that are applicable to file formats; the InSPECT project is working on identifying properties that apply to content types, such as images or e-mails; and the Planets project is investigating advanced significant characteristics and uses them in preservation planning.