See github thread sendwithmessage for Smileycoin

Can send messages by coding it into the blockchain

smileycoin-cli sendwithmessage BEtZyyYqDXqmRJJ45nnL15cuASfiXg9Yik 1000 "Hello, Betzyy"

See transaction daf75d1ae31877b51856b4dee931600a5a5db819f52a5d98627f8a070a72b723:

https://chainz.cryptoid.info/smly/search.dws?q=daf75d1ae31877b51856b4dee931600a5a5db819f52a5d98627f8a070a72b723

Note how the coding uses ASCII characters 32-128 (0x20-0x7F), requiring 2 bytes per character, see http://www.asciitable.com/ (subtracting 32 dec from each ASCII code)