Hey, could anyone explain to me what this code do - mainly, the two rules at the end? I'm somewhat new to .htaccess syntax and whatnot

# subdomain logic
RewriteEngine On
RewriteOptions inherit
RewriteCond %{HTTP_HOST} !^www\.domain\.com [NC]
RewriteCond %{HTTP_HOST} !^domain\.com [NC]
RewriteCond %{HTTP_HOST} ^([A-Z0-9a-z-]+)\.domain\.com [NC]
RewriteCond %{DOCUMENT_ROOT}/%1 -d
RewriteRule ^(.+) %{HTTP_HOST}/$1 [C]
RewriteRule ^([0-9A-Za-z-]+)\.domain\.com/?(.*)$ %{DOCUMENT_ROOT}/$1/$2 [L]
# end subdomain logic

The problem is my server always sends a "Vary: Host" HTTP header with subdomains. This causes my subdomains to not work correctly with IE and all of it's shell-browsers. I can see that the first two RewriteCond-itions basically exclude the base domain and www prefix - which, possibly by coincidence, do not have the "Vary: " HTTP header problem.

Could anyone confirm what the two rules actually do?

Thanks,
//KiroS

I do need a confirmation sometime soon. My tech support thinks it's my fault and they keep closing my support ticket unless I can supply a reason and a solution... Some tech support...