The details pane also allows for the change of some textual metadata such as author and title in files that support them within Windows Explorer. A new type of metadata called tags allows users to add descriptive terms to documents for easier categorization and retrieval. Some files support open metadata, allowing users to define new types of metadata for their files. Out-of-the-box, Windows Vista and Windows Server 2008 supports Microsoft Office documents and most audio and video files. Support for other file types can however be added by writing specialized software to retrieve the metadata at the shell's request. Metadata stored in a file's alternate data stream only on NTFS volumes cannot be viewed and edited through the summary tab of the file's properties anymore. Instead, all metadata is stored inside the file, so that it will always travel with the file and not be dependent on the file system.