Message with transaction

@Tom_Stafford For now you can use for that yes. We recently created an own CIP-0020 especially for sending messages/comments/memos along with transactions. Take a look at those links:

So first, please show your support for this CIP on Github. Second, if you are going to attach the metadata-json on a cli transaction as @bwbush wrote above, please use the format specified in the CIP-0020 with metadatum label 674 and the messages in an array format.