Will the Real Barb Please Stand Up

"These are the Barbs I know, I know.  These are the Barbs I know.  Some of them are Barbaras but most of them are Barbs".
...from New Kids in the Hall, These are the Daves I know I know.

We have three Barbs (and two Donnas) joining us on our wonderful cruise.  In order to reduce confusion, please use the first initial of your last names when you place your name on your swaps, or entering contests.

I just checked and the last name initials are all different.  Phew!  What a relief.