Just perusing:
http://perl.apache.org/docs/2.0/devel/core/apache_integration.html#The_Link_Between_mod_perl_and_httpd
and found a small typo.
"STANDARD20_MODULE_STUFF is a standard macro defined in httpd-2.0/include/http_config.h. Currently its main use *if* for attaching Apache version magic numbers,"
Probably mean, "Currently its main use *is *for..."
thanks, speeves cws