Secret word for when child is separated

I've come across this a few times. What do you think of it? Do you use this method of a secret word that only the people who pick up up your child from school (or anywhere) would know?

About Jennifer Lucas
Current: San Mateo, California
Birth: September 12
On since: Apr 6, 2014
I am a Christian, SAHM. We live in California. Married since 2011. Our Son (Benjamin) born in 2013.Daughter Audrey is due January 2016.,