The whole "charge off" / "write off" thing is not what it appears. In reality, its an accounting function somewhat tied up in IRS rules that allows a creditor to move debts from the "active" to "inactive" categories on their bookkeeping. "Inactive" or "bad debts" can sometimes be charged against income on which the creditor must pay taxes. Depends on whether the creditor keeps their books on a cash or accural basis. Most big companies use accrual.
What it mean to you? Not much, I'm afraid. The creditor can still pursue the debt and even charge interest on it...up until the point where its "charged off / sold to another lender" in which case the new owner hassles you. There's a lot of discussion as to whether or not the new owner is entitled to the full amount of the debt, but that won't stop them from trying to collect it.