This Technote describes the on-disk format for an HFS Plus volume. It does not describe any programming interfaces for HFS Plus volumes.
This technote is directed at developers who need to work with HFS Plus at a very low level, below the abstraction provided by the File Manager programming interface. This includes developers of disk recovery utilities and programmers implementing HFS Plus support on other platforms.
This technote assumes that you have a conceptual understanding of the HFS volume format, as