Due to a constraint of the built-in browser in a Handy phone (called NTT i-Mode), the former version of TAM could not be used in the Japan market. The issue was resolved by the decline of Japan-specific Handy phones. Cookies were not supported in i-Mode browser ver.1, which had the highest market share in Japan. Hence, sessions between that browser and WebSEAL could not maintain the session state using a cookie. The constraint had widespread implications. Some examples: re-authentication, session affinity, cookie-based failover mechanisms. Besides, IBM Japan declared that all browsers built in Handy phones were not supported officially in that version. Rather than a weakness of the WebSEAL specification, that constraint was caused by the insufficient i-Mode browser specification, which was developed by NTT Docomo. Considering the negatives, we could not use WebSEAL for Handy-phone facing applications. (A workaround might exist, but the industry-standardized manner of using cookies was in our favor.)