On April 18, the Securities and Exchange Commission issued a final rule adopting an amendment to Rule 146(b) under the Securities Act of 1933 to designate securities listed, or authorized for listing, on the Nasdaq Capital Market tier of The NASDAQ Stock Market LLC as covered securities under Section 18(b) of the Securities Act. Covered securities are exempt from state law registration requirements as provided in Section 18(a) of the Securities Act. The amendment to Rule 146(b) also includes adding securities “authorized for listing” on a market named in Rule 146(b).

http://www.sec.gov/rules/final/2007/33-8791.pdf