-- https://docs.oracle.com/en/database/oracle/oracle-database/23/lnpls/plsql-language-fundamentals.html
<<outer>>  -- label
DECLARE
  birthdate DATE := TO_DATE('09-AUG-70', 'DD-MON-YY');
BEGIN
  DECLARE
    birthdate DATE := TO_DATE('29-SEP-70', 'DD-MON-YY');
  BEGIN
    IF birthdate = outer.birthdate THEN
      DBMS_OUTPUT.PUT_LINE ('Same Birthday');
    ELSE
      DBMS_OUTPUT.PUT_LINE ('Different Birthday');
    END IF;
  END;
END;
/