Indicates whether conversation-level security information is required on incoming attaches designating this TP name. Conversation-level security verification is always performed on those requests that include security information. yes - Indicates that conversation-level security information is required. ATTACHs designating the transaction program must carry a user_id and either a password or an already verified indicator. no - Indicates that no security information is required. ATTACHs designating the transaction program can omit or include security information.