Beware of the Homeschooler Impersonators!

This is the actual email exchange I had with the owner of a small bookstore when I asked about giving homeschoolers the "educator's" discount. Luckily, I think she might err on the side of trusting people and give parents who say they homeschool the benefit of the doubt. It's sad that there are parents out there who would pretend to be homeschoolers just to save a few bucks.
Hi Trisha,
We need help with this.  We value those who are homeschooling as educators, however, we do not know how to differentiate and identify them for who they are when they walk through the door. 
How do you differentiate and identify other teachers when they walk through the door? Secret handshake? Scarlet Letter "H"? Denim jumpers? There's really no need to discriminate. If you ask Every Single Person who walks through the door: where do you teach? what grade? then you will know who the homeschoolers are by their answers: I would answer: I teach in Los Altos at Adobe Creek Academy, I teach grades 3, 2, and K.
When I look at the B&N  Educator's Discount Application, it appears that all you have to do to claim Homeschooling status is check the box.  Is there more to it?
No, there isn't. 
You could do what RAFT does, which is a little bit more of a screening I think, but if someone takes the time to fill out the form ahead of time, odds are, they're legitimate. 
Is there a large problem with public/private school parents going around town impersonating homeschoolers for a book discount that I don't know about? {Thank goodness I'm keeping away from that criminal element}
I guess you could post a sign saying: "Parents - if you send your children to school for the day please do not pretend to be a hardworking homeschooling parent" or, better yet, "Homeschooler Impersonators will be prosecuted to the full extent of the law."
If homeschooling parents were able to show an affiliation with a school, etc., for ex, it would make it easier for us to differentiate.
It is not possible for an independent homechooler to show an affiliation with a school. There are some parents who homeschool through a public charter school like Ocean Grove Charter school which might give out ID cards, I'm not sure. But I have no such card. So I guess you'll just have to take my word for it....
Let me know your thoughts and thanks for the nudge,
Thank you for at least considering it.
Tricia