Apache Reference: mod_setenvif, SetEnvIfNoCase

SetEnvIfNoCase

Define Environment Variables Based on HTTP Attributes (nocase)
Syntax: SetEnvIfNoCase attribute pattern [!]var[=val] [...]
Example: SetEnvIfNoCase Request_URI ".*\.gif$" isgif
Since: Apache 1.3

This directive is semantically identical to the SetEnvIf directive. It differs only in that the regular expression matching is performed in a case-insensitive manner.