The Central Index Key (CIK) is a unique identifier used by the SEC to identify filing companies. By requiring users to enter the CIK when creating a new form in the Listing Center, Nasdaq can extract information from our system and use it to pre-populate certain fields in your form, such as your company's name, address, board members and auditor.  You can look up the CIK for your company using the following link: http://www.sec.gov/edgar/searchedgar/cik.htm.