PROCEDURE containing ENTRY statements must return aggregate values BYADDR

Problem:

The following compiler errors are generated in MFE, but  not in z/OS PL/I compiler :

The message I get is:

IBM2052I S A function defined by a PROCEDURE containing ENTRY statements must return aggregate values BYADDR. : "C:\\MFUSER\\SOURCE\\NAME.PLI"(1122)

IBM2053I S A function defined by an ENTRY statement must return aggregate values BYADDR. : "C:\\MFUSER\\SOURCE\\NAME.PLI"(1134)

I can change the source code so I don't get this messages using BYADDR but I'm not able to understand the consequences, if there are any.

Please advice.

attached is a small project.

Resolution:

Use the additional directive DEFAULT(RETUrNS(BYADDR))

or change the statement

HUGO_T: ENTRY(HUGO) RETURNS(CHAR(15);      

to         

HUGO_T: ENTRY(HUGO) RETURNS(CHAR(15) BYADDR);