- A typical option tree has the following subdirectories:

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  cfg
    Holds the configuration information.
    Always includes the command dictionary `commands.cnf`.
  exp
    Holds explain files for every command.
  mcr
    Holds macros.
  prim
    Holds primitives.
  test
    Holds test macros and JUnit tests.
- The root directory of an option tree has the following special files:
  version.txt
    Version information about the option tree.
  updates.txt
    Lists any changes made to the option tree after its release.