<IfModule mod_rewrite.c>
RewriteEngine On
##Попадаем в
тему
RewriteRule ^([0-9]*)/?$ index.php?id=$1 [L,QSA]
RewriteRule
^([0-9]*)/([0-9]*)/?$ index.php?id=$1&id_razdel=$2 [L,QSA]
RewriteRule
^([0-9]*)/([0-9]*)/([0-9]*)/?$
index.php?id=$1&id_razdel=$2&id_them=$3 [L,QSA]
RewriteRule
^([0-9]*)/([0-9]*)/([0-9]*)/([0-9]*)/?$
index.php?id=$1&id_razdel=$2&id_them=$3&id_post=$4
[L,QSA]
</IfModule>