Some systems for serialising data that may be useful for sending messages over LoRa.

Protobufs - used by Meshtastic.

BSON - Binary JSON.

“BSON can be com­pared to bin­ary inter­change for­mats, like Proto­col Buf­fers. BSON is more “schema-less” than Proto­col Buf­fers, which can give it an ad­vant­age in flex­ib­il­ity but also a slight dis­ad­vant­age in space ef­fi­ciency (BSON has over­head for field names with­in the seri­al­ized data).”

FlatBuffers - https://flatbuffers.dev/

https://en.wikipedia.org/wiki/Cap%27n_Proto

https://msgpack.org/index.html - used by LXMF / Reticulum