Dependency rules describe the relationships  among  the  files  in  a
    software system and specify the actions MMS is to perform in updating
    those files.

    Format:

      target,... : source,...  [! comment]
              action line    [! comment]

    Targets and sources  are  OpenVMS  file  specifications  or  mnemonic
    names.   A  target  is the file you want updated.  A source is a file
    from which the target is built and can be optional.  You must begin a
    target/source  line  in column 1 of the line, and you must include at
    least one space or tab on each side  of  the  colon.   A  comment  is
    simply a string of text that documents the description file.

    An action line contains a CLI command that specifies how  the  target
    is  to  be built from the source.  An action line must be indented by
    at least one space or tab below the corresponding target/source line.
    When  you  run  MMS,  all  action  lines,  including any comments you
    specified in the description file, are written to SYS$OUTPUT  (or  to
    the file specified by the /OUTPUT qualifier) as they are executed.

    MMS supplies some default, or "built-in," dependency rules.  You  can
    also define your own rules.

1  –  Built-in Rules

    MMS uses built-in rules when you omit the action line or the  source,
    or  both, from a dependency rule.  Built-in rules allow MMS to assume
    dependencies that are not stated  in  the  description  file  and  to
    perform  actions  necessary  to  update  the target.  To decide which
    built-in rule to apply to a dependency, MMS also  uses  the  suffixes
    precedence list.

    Built-in rules also allow you to  access  files  stored  in  OpenVMS,
    CMS,  FMS libraries and records stored in the Common Data Dictionary.

2  –  User-defined Rules

    You can define your own rules in a description file if MMS  does  not
    supply  a built-in rule that meets your needs.  Once you define a new
    rule, MMS uses  it  every  time  it  builds  your  system  with  that
    description file.

    Format:

      .SRC.TAR     [! comment]
              action line...     [! comment]

    .SRC is the source file type, and .TAR is the target file type.   The
    comment  is  a  string  of text that documents your rule.  The action
    lines specify the CLI commands that MMS should execute  to  update  a
    file  of  the  target  type from a file of the source type.  Both the
    source and target file types must appear in the  suffixes  precedence
    list.

3  –  Suffixes precedence list

    The suffixes precedence list is a list of  all  the  file  types  MMS
    recognizes,  arranged in a predetermined order.  MMS uses the list to
    decide which built-in rule to apply based on the order of  the  types
    in the list, the file type of the target currently being updated, and
    the existence of source files in the specified directory.

    You can  alter  the  suffixes  precedence  list by using  one  of the
    .SUFFIXES... directives.