The U.S. Coast Guard issued a Navigation and Vessel Inspection Circular (NVIC) providing guidance for implementation of the Transportation Worker Identification Credential (TWIC) program in the maritime sector. The NVIC explains the enrollment and issuance process and provides clarification of the regulations. Full implementation of the TWIC program in the maritime sector is planned for September 25, 2008. After that date (and earlier at some facilities), persons may not be allowed unescorted access to secure areas unless they possess a valid TWIC card. The NVIC includes a blank placeholder for the detailed implementation schedule. 72 Fed. Reg. 37537 (Source: HK Law).