The Transportation Security Administration (TSA) and the US Coast Guard issued an Informational Bulletin reminding maritime workers and regulated facilities that the prototype Transportation Worker Identification Credentials (prototype TWICs) issued on a test basis to participating workers from 2004 to 2006 were only valid during that trial phase and may not be used for the purpose of obtaining unescorted access to regulated maritime facilities once the compliance date for that facility comes into effect. Workers still in possession of a prototype TWIC should promptly apply for a valid TWIC.
(Source: Holland & Knight)