DM (for Data Management) files are very similar to EDB files.  The EDB
format is seen as a useful format and many pople will have invested effort
in transforming their source data into this format.  It is hoped that
existing tools will only require slight modification to produce this format.
The advantage that DM files have over EDB files is that the syntax allows
the specification of entry/atribute deletion.  Comparing the previous
version of the DM file with the current version, by using dmdiff, allows
changes in the source data to be represented in this syntax.  Other tools
can then process this data into a set of directory operations, and changes
to the directory can be made using DAP, rather than by altering EDB files and
restarting the DSA.

The differences between the formats are as follows:

                 EDB                      DM

Org units within organisation       Flat file with imbedded info 
represented in UNIX directory       saying where entries should be loaded 
tree structure                      in the DIT

Files start with                    File don't start with ...   
MASTER
date in UTC format

                                    File contains "rootedAt" info

                                    Syntax includes mechanism for 
                                    specifying deletion of an entry /
                                    attribute


dmdiff <old_file> <new_file>

produces a difference version of the 2 DM files.

Example of a DM file produced by dmdiff
----------------------------
rootedAt=c=gb@o=University College London@ou=Association of University Teachers Local Office

# ATTRIB CHANGES FOR THIS ENTRY
cn= A.U.T. OFFICE
telephoneNumber = +44 71-380-7230
!telephoneNumber = +44 1-380-7230

# ATTRIB CHANGES FOR THIS ENTRY
cn= R Jones
telephoneNumber= +44 71-380-7230 
!telephoneNumber= +44 1-380-7230 

rootedAt=c=gb@o=University College London@ou=American Institute for Foreign Studies

# ATTRIB CHANGES FOR THIS ENTRY
cn= AMERICAN INSTITUTE FOR FS
telephoneNumber = +44 71-387-7050 x 2945
!telephoneNumber = +44 1-387-7050 x 2945

rootedAt=c=gb@o=University College London@ou=Anatomy and Developmental Biology

# ATTRIB CHANGES FOR THIS ENTRY
cn= J Aberdeen
telephoneNumber= +44 71-387-7050 x 3341 (Lab)
telephoneNumber= +44 71-387-7050 x 3329 (Office)
!telephoneNumber= +44 1-387-7050 x 3341 (Lab)
!telephoneNumber= +44 1-387-7050 x 3329 (Office)

# ATTRIB CHANGES FOR THIS ENTRY
cn= A Ainsworth
telephoneNumber= +44 71-387-7050 x 3396 
!telephoneNumber= +44 1-387-7050 x 3396 

# ATTRIB CHANGES FOR THIS ENTRY
cn= P Ainsworth
telephoneNumber= +44 71-387-7050 x 3387 
!telephoneNumber= +44 1-387-7050 x 3387 
