The registry is for all 6,749 RPO Z25 Ruby Red Corvettes built in 1993. Since we have no dues or fees, you are automatically a member by owning a RUBY. It is absolutely free. There are no dues or fees of any kind. We support ourselves and the NCM by selling items. The "number" of your Ruby is the last 5 digits of the VIN. The last five digits are known as your Ruby's "Serial Number". It represents the number of 1993 Corvettes that were built in sequence.