File Properties

There are three kinds of file properties: , core, custom, and extended. The core file properties of a package enable users to discover, get, and set common sets of properties from within that package, regardless of whether it’s a WordprocessingML, SpreadsheetML, or PresentationML package. Extended file properties are specific to Office Open XML packages, while custom file properties are defined by the user, with each custom file property having a name, a value, and a type.