When the IF clause of a IF-THEN-ELSE structure does not complete successfully, the ELSE clause is unnecessary.

Noncompliant Code Example

BEGIN
  IF condition THEN
    RETURN value;
  ELSE
    value := NULL;
  END IF;
END;

Compliant Solution

BEGIN
  IF condition THEN
    RETURN value;
  END IF;
  
  value := NULL;
END;