2.1 NT Backup File

An NT backup file is made up of zero or more backup streams that appear one right after the other. A backup stream is a logically related collection of data that is related to one file. For example, the file's contents are a backup stream; its security information is a backup stream, and so on. Each backup stream in an NT backup file consists of a WIN32_STREAM_ID (section 2.2) header, followed by the file-specific data for that backup stream.

An implementation that creates a backup stream for an NT backup file for use over-the-wire MUST use only the dwStreamId values that are specified in section 2.2 when creating a backup stream. An implementation reading an NT backup file, and then creating a file based on it, MUST fail if its dwStreamId value is not one of those specified in section 2.2.

If an unrecognized or unused dwStreamId value or an otherwise malformed NT backup file is encountered, an implementation MAY process the remainder of the NT backup file. An implementation MAY delete the portion of the file it has created upon finding a malformed NT backup file.<1>