ErrorDocument 404 /404.html

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_URI} !^/robots\.txt$
RewriteCond %{HTTP_HOST} !^www\.mydomain\.com$ [NC]
RewriteRule ^(.*)$ http://www.mydomain.com/$1 [R=301,L] 
</IfModule>

RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} "android|blackberry|ipad|iphone|ipod|iemobile|opera mobile|palmos|webos|googlebot-mobile" [NC]
RewriteCond %{HTTP_HOST} "!m.domain.de" [NC]
RewriteRule (.*) http://m.domain.de/ [L]

RewriteRule ^catalog/([^/]+) /catalog.php?page=$1 [NC]

# Follow symbolic links in this directory
Options +FollowSymLinks

# Set the default handler
#DirectoryIndex index.php

# URL rewrite rules
<IfModule mod_rewrite.c>
   RewriteEngine On
   RewriteBase /
   ## Category redirect
   RewriteCond %{REQUEST_FILENAME} !-f
   RewriteCond %{REQUEST_FILENAME} !-d
   RewriteRule  ^([\w\-]+).html$ /index.php?seo_name=$1 [L]
   RewriteRule  ^map.xml$ /index.php?section=google_xml_map [L]
</IfModule>

index.php?a=1&b=2&c=3

a=1 => webtest_1
a=2 => webtest_2
...
a=x => webtest_x
-------------------------------
b=1 => photo_1
b=2 => photo_2
...
b=x => photo_x
--------------------------------
c=1 => pc_1
c=2 => pc_2
...
c=x => pc_x
--------------------------------
...
...
...
--------------------------------
z=1n => last_variable_1n
z=2n => last_variable_1n
...
z=xn => last_variable_xn

Options +FollowSymlinks
RewriteEngine on

RewriteRule ^webtest_1/photo_2/pc_3\.html$ /index.php?a=1&b=2&c=3 [L]
RewriteRule ^webtest_2/photo_1/pc_1\.html$ /index.php?a=2&b=1&c=1 [L]
...
...
...

RewriteEngine on
RewriteCond %{HTTP_USER_AGENT} iPhone|iPad|iTouch|iPod|palm||android
RewriteCond %{REQUEST_URI} !^/my-iPhone-site/
RewriteRule .* /mobile/ios/ [R]

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

# END WordPress