DICOM messages that are transferred across a DICOM Associate connection include a Command Set and may or may not include a Data Set. The Command Set is a specialized Data Set that contains information about the action to be taken, such as Request, Response, Find, Get, Move, Action, etc. Since the Command Set is a Data Set, it consists of one or more Data Elements. An accompanying Data Set contains either the Data Set on which to perform the command, or the Data Set resulting from a command.
Each Command Set has its own specific set of Data Elements. For more information on Command Sets in general, refer to the DICOM Standard.
Since a Command Set is a specialized Data Set, it is created the same way a Data Set is and then initialized as a Command Set using the DicomDataSet.InitializeCommandSet method.
To obtain information about an existing Command Set, use DicomDataSet.InformationCommand.