The

Syntax: SetEnvIfNoCase attribute regex envar[=value] [...]
Default: none
Context: server config
Override: none
Status: Base
Module: mod_setenvif
Compatibility: Apache 1.3 and above

The SetEnvIfNoCase is semantically identical to the SetEnvIf directive, and differs only in that the regular expression matching is performed in a case-insensitive manner. For example:

   SetEnvIfNoCase Host Apache\.Org site=apache
  

This will cause the site envariable to be set to "apache" if the HTTP request header field Host: was included and contained Apache.Org, apache.org, or any other combination.