2.2.7.1.3 SearchFolderID

If the Id field is set to SearchFolderID, the value of the Data field is a 16-byte field. When the application creates a persistent search folder, as specified in [MS-OXOSRCH] section 2.2.1, it MUST set this field on the folder to the same value as the PidTagSearchFolderId property ([MS-OXOSRCH] section 2.2.1.2.1) on the message.