An application can create, query, and set extended attributes (EAs) for any file object.

The application can define extended attributes for a file when the file is created with DosOpen. Similarly, the application can define EAs for a directory when the directory is created using DosCreateDir.

An application can define EAs for existing file objects by referencing the file object by its handle and calling DosSetFileInfo, or by referencing the file object by its name and calling DosSetPathInfo.

An application can examine the EAs for a file object by referencing the file object by its handle and calling DosQueryFileInfo, or by referencing the file object by its name and calling DosQueryPathInfo. The application can also call DosEnumAttribute, using either the file object's handle or its name, to get information about the file object's EAs.

In addition, an application can search for file objects and specify that certain EAs be returned by calling DosFindFirst.