Your opponents have a right to know your system. They do not have the right to know what is in your hand. If the contents of your hand differ from the explanation of your system, then either:
a) The explanation is wrong. This is misinformation and your opponents may have been damaged; or
b) You have departed from your system, either accidentally (a mis-bid) or deliberately (a psyche).
When a mis-bid occurs you may well achieve a good score. Opponents are often very unhappy that the result of your messing things up leaves them with a bad score and you with a good one. However, unless there is evidence that your partner made some allowance for you forgetting (called fielding the mis-bid), the score stands, irrespective of the damage done. If a mis-bid is fielded, the hand is scored 60/40%.
What is misinformation?
a) Failure to alert an alertable call constitutes misinformation.
b) A relevant but incomplete explanation, even when perfectly accurate, constitutes misinformation.
c) A mistaken explanation, given to an opponent who asks for an explanation, is misinformation.
d) A wrongly completed convention card, which misleads an opponent who looks at it, is misinformation.