I was trying to think of a good example, but the following table from RFC 5424 [1] might be a good starting point. I guess unknown could be used for the top 3 conditions.

           Numerical         Severity
             Code

              0       Emergency: system is unusable
              1       Alert: action must be taken immediately
              2       Critical: critical conditions
              3       Error: error conditions
              4       Warning: warning conditions
              5       Notice: normal but significant condition
              6       Informational: informational messages
              7       Debug: debug-level messages

[1] https://datatracker.ietf.org/doc/html/rfc5424