Documentation/stable_api_nonsense.txt ;-)
This is just as "bad" as the loglevel parameter. Because you'd have
to parse str[0] in _every_ write() function. Furthermore, the string
that is being printed also goes to klogd/syslog, including the <N>
tag already. If you now add a color byte in the KERN_* macros, then
that color byte would also go to syslog. Not good.
(Paraphrased one paragraph above.)
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