If an ad states 2 deposit rates for separate products - isn't true they need to be the same size? I am looking for this in Reg. DD and cannot easily locate it. Thanks

If you are talking about two separate products - there is no such requirement.

The rule is that if you state an interest rate, it may not be more prominent than the state APY. You could list two IBAs and have one more predominant than the other so long as it isn't misleading and appears that it is somehow connected to the other account. Say if you listed a high rate MMDA APY, but put it next to the savings product description that was paying 3% less. But that is a different issue.