We didn't have any special wording, BUT be sure that you put down how old your child is and a rough estimate of what size you think he will be. That's hard to guess of course, but make sure that people know NOT to buy 0-3 month sized clothing! We had a few people buy us small outfits - I guess they just didn't remember that she is ALREADY 3 months old!
These are the things that I took to the shower:
a list of the steps of the process
a map of Guatemala to show everyone where she was born
pictures of her
Everyone enjoyed learning more about the process.
Have a fun time!!!