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.