The types of Configuration Variables are as follows:

• Path Configuration Variables tell the product where (in what directory) to find files.

  For example, if you specify a DGN file to open when starting the application, it searches for the DGN file in the directory or directories specified by the MS_DEF Configuration Variable. The first time you select File > Open, the first directory specified by MS_DEF displays in the Open dialog.

• Directory Configuration Variables tell the product where to save files. For example, MS_PLTFILES specifies where to save print files. The first time you save a print to a file, the directory specified by MS_PLTFILES displays in the Save Print As dialog.
• Filename Configuration Variables specify a file to use for a particular purpose. For example, MS_DESIGNSEED specifies the seed file that the product copies to create a new DGN file (if you do not select a different seed file). For example, MS_DESIGNSEED specifies the default seed file.
• Keyword Configuration Variables specify certain default settings. For example, MS_LINKTYPE specifies the user data linkage types recognized by the database server. The possible values or keywords are BUDBC, DMRS, ORACLE, OLEDB, and ODBC.