I'm trying to set various types of mobile-specific configuration based on environment variables.
The psudocode (psudoconfig) I was trying to do was something like:
<if environment variable = iphone> ErrorDocument 404 /error_pages/404.iphone.html </if>
Where the env variable is set by the UA of the browser. I just haven't found a way in apache conf files to test for an environment variable - just to set it. Plenty of ways with SetEnfIf logic to SET environment variables, but not in the config or rewrite files to then test for variables & set results.