How do I ignore a directory in mod_rewrite?

Try putting this before any other rules.

RewriteRule ^vip - [L,NC] 

It will match any URI beginning vip.

• The - means do nothing.
• The L means this should be last rule; ignore everything following.
• The NC means no-case (so "VIP" is also matched).

Note that it matches anything beginning vip. The expression ^vip$ would match vip but not vip/ or vip/index.html. The $ may have been your downfall. If you really want to do it right, you might want to go with ^vip(/|$) so you don't match vip-page.html

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d

This says if it's an existing file or a directory don't touch it. You should be able to access site.com/vip and no rewrite rule should take place.

The code you are adding, and all answers that are providing Rewrite rules/conditions are useless! The default WordPress code already does everything that you should need it to:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

Those lines say "if it's NOT an existing file (-f) or directory (-d), pass it along to WordPress. Adding additional rules, not matter how specific or good they are, is redundant--you should already be covered by the WordPress rules!

So why aren't they working???

The .htaccess in the vip directory is throwing an error. The exact same thing happens if you password protect a directory.

Here is the solution:

ErrorDocument 401 /err.txt
ErrorDocument 403 /err.txt

Insert those lines before the WordPress code, and then create /err.txt. This way, when it comes upon your WebDAV (or password protected directory) and fails, it will go to that file, and get caught by the existing default WordPress condition (RewriteCond %{REQUEST_FILENAME} !-f).

In summary, the final solution is:

ErrorDocument 401 /misc/myerror.html
ErrorDocument 403 /misc/myerror.html

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

I posted more about the cause of this problem in my specific situation, involving Wordpress and WebDAV on Dreamhost, which I expect many others to be having on my site.