PeopleSoft Enterprise

By name =)? You can have a package specification only with no implementation, and so as You guess there may be some internal mechanism but I haven't seen it documented on user guides. Perhaps DBA's may have knowledge on how those structures are stored internally, as the parsed and compiled code is stored and loaded for execution, not the text we see in user|all|dba_source.

One way:

SELECT name, referenced_name, referenced_type
FROM dba_dependencies
WHERE name = 'UTL_FILE'
AND referenced_type like '%PACKAGE%'
UNION
SELECT name, referenced_name, referenced_type
FROM dba_dependencies
WHERE referenced_name = 'UTL_FILE'
AND referenced_type like '%PACKAGE%';