Simplify the following text for a Grade 13 native English-speaking person.
Original: The original information may or may not appear literally in the encoded output ; codes that include the unmodified input in the output are systematic , while those that do not are non-systematic .
Simplified: The original information may or may not appear in the encoded output ; codes that include the unmodified input in the output are systematic , while those that do not are nonsystematic .