How does kafka broker treat log.message.format.version if -lVx is not specified?

Hello .

I have a kafka broker 2.4.0 running with below message format
setting both in broker and topic.

# Broker configuration
inter.broker.protocol.version = 2.4-IV1
log.message.format.version = 2.4

# Topic configuration
message.format.version=2.4-IV1

I just checked the documentation and realized log.message.format
requires -IVX after minor version.

https://kafka.apache.org/documentation/#log.message.format.version

How does a broker treat log.message.format.version if "-IVX" is not specified?

I ended up with below code but looks like I am not looking at the right place...

https://github.com/apache/kafka/blob/7f90a58b69cd0eb63ba122b41e6ef6195b0a5d98/core/src/main/scala/kafka/server/KafkaConfig.scala#L126

Thanks,
Yu
--
Yu Watanabe

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