A minimal history is a history entry without log and prelude.
The corresponding config entry is ffmpeg.log.max_minimal_history. This value is
added on top of the ffmpeg.log.max_history value. I.e. the latest max_history
entries contain the log and prelude, and the remaining entries don't have the
log and prelude. In total there are max_minimal_history+max_history history
entries.
If you want no history, set both values to 0.
If you want only full history, set max_minimal_history to 0.
If you want only minimal history, set max_history to 0.