No, just make sure you tell the server at the restaurant when you are ordering. Unless you have booked a Dinner show or one of the restaurants that requires a full payment at time of booking (Cinderella's) you would not "need" to tell them when booking the ADR, although they like to note it on the reservations as long as the server knows it is not an issue.
Don't have to tell them now. But when making ours she asked. I also made some ADR's and had to tell her which we were paying for and witch were DP. Seems that when I said we were oop I got the exact times I wanted. Some of the DP times, I had to take what they offered. And I called at the 6 month date.
You don't have to worry about it. The servers at the restaurants will ask if anyone has a dining plan. They basically trip over themselves before you order to make sure they have everything correct. They will do everything to make sure you get what you are entitled to. I felt bad because we weren't on the dining plan!