Two runtime elements in a run unit can reference common file connectors in the following circumstances: 
  
 
   
	 - An external file connector can be referenced from any runtime element which describes that file connector. 
	 
- If a program is contained in another program, both programs can refer to a common file connector by referring to an associated global file-name either in the containing program or in any program which directly or indirectly contains the containing program.