When supporting a system you frequently need a view of the aggregated errors that the system is generating.
However there will sometimes be an error in the logs that you just can’t fix or it is not worth fixing yet.

Exclude these from the main view as they will mask out real problems further down the frequency table.

This is especially important if you are trying to fix the most frequent error each week, If the same error is always there no progress will be made.

A log message that is an error is a failure of a system to do something. Typically something can be done to improve matters (a retry, an alert). If you are going to log them look at the logs on a regular basis.

If a client side error was caused from a system outside your direct application it is fine to make another call to store that error,

Give your log messages a useful correlation id. Natural ones are best (the order id being processed) but artificial ones are also useful, if sent through the system.