Transmission of data messages up to 1000 bytes in length from any account to any other account.
Arbitrary messages are limited only by length. Any string can be transmitted, using any data structure or form of data encryption. Encoding, decoding, linked messages, data structures, and more can be implemented by any application that uses the system.
The base implementation allows for the transmission of simple, unencrypted text messages between accounts, but since the messages are truly "arbitrary" the range of possible applications is vast. Secure messaging, torrent applications, voting systems, data storage systems and even simple distributed applications have been suggested.
Arbitrary messages were implemented at a block height of 40,000 (approximately January 11, 2014)