Rant: Target’s Gift Messages

I just placed an order on Target.com for a baby gift. Since I was shipping the gift to the mom-to-be and wouldn't be able to attend her shower in person, I wanted to include a gift message. I attempted to include the following message:

Congratulations! We're so excited for you. We can't wait to meet the little one!

Love, Andrea & William (Mike)

(We had to go with a turtle theme; the mascot of William's alma mater is a terrapin, after all.)

Yet Target told me that they could not include my message because it contained special characters or unacceptable words. Um, what?

On top of that, Target had erased my entire message and didn't bother to tell me which characters or words were unacceptable. So I tried again, removing all line breaks.

Still unacceptable. I tried again, removing all parantheses and the ampersand. Still unacceptable. I tried again, thinking that perhaps Target's vocabulary wasn't quite large enough to include "alma mater" and "terrapin," so I changed them to "college" and "turtle," respectively. Still unacceptable.

When I was on the verge of hitting my computer, I simply tried,

Congratulations! Love, Andrea and William

Finally, Target deemed my message acceptable and attached it to the gift.

But Target, I'd really like to know...
What was unacceptable about my original message?