Going through SEA yesterday, I was admonished by a TSA agent for packing a sippy cup of milk for my 2yo. He let me keep the milk but sent me off with a warning that drinks were only allowed for kids under 18mos and that not every TSA agent would be as nice as him. I told him that in 6 years and dozens of flights carrying milk for my kids at ages >18 mos I had never heard this from one single agent. He told me that anyone who didn't stop me and confiscate it wasn't following the rules.

Anyone know the *actual* rule on this? Frankly, it wasn't strictly necessary to bring, but I know that milk can be hard to find on flights these days and that kids don't magically stop drinking milk at 18 mos. (heck, they make toddler "formulas" for kids up to 36 months).