I understand that there are rules regarding which categories your site should be listed in, but I believe that the rules should be the SAME for ALL SITES. The PREEMIE clothing section is listed for PREEMIES EXCLUSIVELY. There is 1 site in there that sells preemie, newborn and toddler clothing. I sell the same sizes and was just removed today. I believe this other site should be also be removed from preemie and placed in the proper section as well.
Head on over to the category page, click on the update listing link and drop a dime. Courteously explain why you think it should be moved (no need to mention your site at all) and somebody will consider it. Anybody can raise update listing requests about a website, not just the owner . Most editors process update listing requests with a higher priority than listing suggestions and some wide ranging editors concentrate on them.
I've just amended a coupla listings there and maybe one was the one you're complaining about. Thanks for the tip.
Read the description for each category in DMOZ. But the editors have the decision whether your site is suitable to a category or not, and you have no choice. That's DMOZ.