SP2-0804: Procedure created with compilation warnings

SQL> alter session set plsql_warnings = 'enable:all';
SQL> create or replace procedure tq84_ppp as begin null; end;
2  /

SP2-0804: Procedure created with compilation warnings

SQL> show errors
Errors for PROCEDURE TQ84_PPP:

LINE/COL ERROR
-------- -----------------------------------------------------------------
1/1      PLW-05018: unit TQ84_PPP omitted optional AUTHID clause; default
         value DEFINER used