The most relevant code for Shutters today is the: IBC - International Building Code (2000)
IBC is being adopted and enforced in most states in the U.S.. See map below:

Future Adoption Codes enforced State Wide Codes enforced at local level

Effective Feb. 1. 2003 the International Code Council (ICC) became one consolidated organization. This new Organization unifies BOCA (Building Officials and Code Administrators International), ICBO (International Conference of Building Officials) and SBCCI (Southern Building Code Congress International). For more detailed and up to date information go to: http://iccint.intlcode.org/government/adoptions.htm

Here is a excerpt of the code that pertains to the protection of openings

2000 International Building Code  1609.1.4 Protection of Openings.  In wind-borne debris regions, glazing in the lower 60 feet in buildings  shall be assumed to be openings unless such glazing is impact  resistant or protected with an impact-resistant covering meeting the requirements of an approved impact-resisting standard or  ASTM E 1996 and of ASTM E 1886 referenced therein as follows:    1. Glazed openings located within 30 feet of grade shall meet the  requirements of the Large Missile Test of ASTM E 1996.  2. Glazed openings located more than 30 feet above grade shall meet  the provisions of the Small Missile Test of ASTM E 1886.  HURRICANE-PRONE REGIONS. Areas vulnerable to hurricanes defined as:  1. The U.S. Atlantic Ocean and Gulf of Mexico coasts where  the basic wind speed is greater than 90 mph and  2. Hawaii, Puerto Rico, Guam, Virgin Islands and America Samoa.  WIND-BORNE DEBRIS REGION. Areas within hurricane-prone regions  within 1 mile of the coastal mean high water line where the basic wind speed  is 110 miles (48.4 m/s) per hour or greater, or where basic wind speed  is 120 miles (52.8 m/s) per hour or greater, or Hawaii.