This isn't specific to Disney, but just something to consider:
DH is a volunteer firefighter/EMT and has told me several times that emergency personnel check for ID in pockets, as bracelets and as necklaces. They don't look for shoe tags, tattoos, or ID that might be anywhere else. Shoe tags and tattoos are fine in a situation where your child is lost and can point out the ID. But in an emergency where you child may be unconscious or otherwise unresponsive, these things won't be checked. Just something to be aware of.
DS wears a medical bracelet at all times. His diagnoses are engraved on the outside; personal and contact information is engraved on the inside.
Gena
DS, age 11 and always amazing
“Autistics are the ultimate square pegs, and the problem with pounding a square peg into a round hole is not that the hammering is hard work. It's that you're destroying the peg." - Paul Collins, Not Even Wrong