FLAGGER
FLAGGER {OFF | ENTRY | INTERMED[IATE] | FULL}
Checks to make sure that SQL statements conform to the ANSI/ISO SQL92 standard. You may execute SET FLAGGER even if you are not connected to a database. Standard flagging will remain in effect across SQL*Plus sessions until a SET FLAGGER OFF (or ALTER SESSION SET FLAGGER = OFF) command is successful or you exit SQL*Plus. When standard flagging is enabled, SQL*Plus displays a warning for the CONNECT, DISCONNECT, and ALTER SESSION SET FLAGGER commands, even if they are successful.