RewriteCompatibility2 directive

Description: Enables or disables ISAPI_Rewrite 2.x compatibility mode
Syntax: RewriteCompatibility2 on|off
Default: RewriteCompatibility2 off
Context: server config, virtual host, directory, .htaccess


This directive enables compatibility features with ISAPI_Rewrite version 2.x and it is required for correct translation of some 2.x rules into 3.0 version syntax. This does not mean that ISAPI_Rewrite 3 will start to understand old syntax without modification. If you have old rules designed for ISAPI_Rewrite 2.x please use translation tool provided with ISAPI_Rewrite manager to translate these rules into new syntax.

For now the only thing changed by setting RewriteCompatibility2 on directive is that it turns off URL pre-normalisation and removal of query string. Apache mod_rewrite remove query string part from the matching URL, while ISAPI_Rewrite 2.x match entire URL including query string. Also meaning of [O] flag will be inverted by this directive.