I don't have an official list, but here are some things I brought.
Diapers
Wipes
Extra plastic bags for stinky diapers
Ziplocs (I kept the wipes in a ziploc for the day because with 3 kids I needed more than I could fit in a travel size package)
Baby food
Disposable spoons
Sippy cup
Snacks
Disposable placemats
Swim diapers
Tylenol
Thermometer
Orajel
Sunscreen
A few teethers/toys
Pacifiers if your child needs them (my middle child used a "binky" so I made sure to have PLENTY and I bought a pacifier attacher to clip it to his shirt so we didn't lose so many)
Disposable bibs
Bottles
Formula (we used powder, easiest in the parks)
Bottle brush and dish detergent to clean cups and bottles
Sun hat for the water (I found a great one in target)
Sun hat for the parks
Sunglasses if your little one will wear them (mine wouldn't

)
Rain cover for stroller
HTH some!
Oh, I also bought a clip (something like hikers would use to go down a steep mountain) to attach rings to the stroller so I could clip toys and sippy cups to the rings. I don't know if they still make any sippy cups with closed handles though. I couldn't find one for our last trip so I had to dig out one of my oldest child's cups. Seems they are making them with open handles now, so they can't be attached like that.