This domain name can’t be used because it contains a protected word or inappropriate language. Please contact support if you feel this is not the case.

Hi, I can´t register my domain cpromo.cz, it always says "This domain name can't be used because it contains a protected word or inappropriate language. Please contact support if you feel this is not the case." I don´t know why? Can you hepl me ? Domain is nickname of Creative Promotion, and a have domain creativepromotion.cz in me own too.  Thank you.