Should I enter him in a toddler spelling contest? :-)

This evening, as we were getting 1-year-old ready for bed, Hubby and I were discussing whether or not it would be worth it for one of us to make a run to the grocery store. I said, "Well, we're all out of m-i-l-k" (spelling it so 1-year-old wouldn't get unnecessarily excited). 1-year-old's eyes lit up, he said, "yeah! yeah!" and began rapidly making the sign for milk. Can someone tell me how my kid learned to spell milk? Maybe Hubby and I will have to come up with a code word for it, just like we have to refer to bananas as "monkey fruit" or "the long yellow things."