Messages are categorized as "event" and "general" messages. Skype has support for sending SMS messages. The service publishes updates by sending event messages. Truemessenger enables users to identify the sender of SMS messages. This is achieved by sending SSDP alive messages. It notified users of new inbox messages, lifestream activity and more. They receive large numbers of unsolicited error messages and other auto-replies. Messenger users are subject to unsolicited messages (SPIM). Only the less secure SMS one-time PIN messages to registered mobile numbers are supported. His campaign employed the use of mass text messages. It introduced Section 66A which penalized sending "offensive messages". This reduces communication and especially avoids problems with many small messages. CAN bus may also be used for communication beyond the standard OBD messages. Facebook posts sharing trite motivational messages. It requires levels of messages that respond to previous messages.