Our institution has chosen to not allow the opt-in and will abide by the proper guidelines. I know that this does not trigger the necessity to send out notices to our customers. However, as a marketing option, we would like to educate customers of our decision. Are there required terms needed for this type of customer notice? Are there any avenues of ideas out there for this type of notice?
Thanks for your help!

If you're not allowing them to opt-in (and not allowing ODs or charging fees), there are no regulatory issues. You may want to notify customers based on a customer service issue, however.

If your bank takes customers overdrawn, intentionally or otherwise, and it charges an overdraft fee it offers an "overdraft service" under Regulation E:

(a) Definition. For purposes of this section, the term “overdraft service” means a service under which a financial institution assesses a fee or charge on a consumer’s account held by the institution for paying a transaction (including a check or other item) when the consumer has insufficient or unavailable funds in the account.

You are only required to run an opt in program if you want to charge fees for overdrafts created by ATM or one time debit card transactions. Clearly, you do not.

Regardless, if you write to your customers explaining the way you handle overdrafts it is an "advertisement promoting the payment of overdrafts" and must comply with Regulation DD, 12 CFR 230.11(b)(1).

They have really made a mess out of this...