3 0 Filter-only sentinel. A LOG event must not use this value. Message text was truncated to the bounded on-wire buffer. Runtime log emitted by Kaptan logging macros, including error. Kaptan wire level. TRUNCATED=1. Receivers ignore unrecognized bits. Number of valid UTF-8 bytes in message; at most 160. Bounded UTF-8 message bytes. Bytes after message_length are zero.