USER_REFS

Description of the user's own REF columns contained in the user's own tables

Columns
   ___________________________
 
   TABLE_NAME
      Name of the table containing the REF column
   COLUMN_NAME
      Column name or attribute of object column
   WITH_ROWID
      Is the REF value stored with the rowid?
   IS_SCOPED
      Is the REF column scoped?
   SCOPE_TABLE_OWNER
      Owner of the scope table,if it exists
   SCOPE_TABLE_NAME
      Name of the scope table,if it exists
   OBJECT_ID_TYPE
      If ref contains user-defined OID,then USER-DEFINED,else if it contains system generated OID,then SYSTEM GENERATED

Related:

Simon Sheppard
SS64.com