Log::Log4perl has these levels–

OFF   FATAL   ERROR   WARN   INFO   DEBUG   TRACE   ALL
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In Catalyst/Log::Log4perl::Catalyst I just pick what makes sense at the time. Fatal and error both sort of define themselves. Warn is something important for the dev to see early and often until fixed. Info… seems a step too much but I have used it when waffling about using debug. Debug for normal, easy to understand flow information that is possible, or prone, to regressions/problems. Trace, the whole enchilada, too much really but some trouble shooting requires it. All… I don’t even think is supported in Catalyst logging… never saw it before tonight.