Apache Reference: mod_rewrite, RewriteLogLevel
Rewrite Engine Logging Level
Syntax: RewriteLogLevel A
Example: RewriteLogLevel 3
Since: Apache 1.2
This directive sets the verbosity degree of the rewriting engine
log file (-> RewriteLog). The level argument is a number between
0 and 9, where 0 disables the log file writing and 9 outputs
even debugging information.