jkm

Или так

RewriteRule ^(.+\.html)&(limit=\d+&)(?:limit)?(start=\d+)$ /$1?$2$3 [L,R=301]

RewriteCond %{QUERY_STRING} ^categoryID=(\d+)$
RewriteRule ^index\.php$  /index.php?route=product/category&path=%1 [L,R=301]

Вставить сразу после RewriteEngine On

RewriteCond %{QUERY_STRING} =format=pdf
RewriteRule ^(.+)/modal$ /$1? [R=301,L]

Возможно так

RewriteEngine on

RewriteCond %{REQUEST_URI}?%{QUERY_STRING} !^/\?r_id=\d+$
RewriteCond %{QUERY_STRING} ^(r_id=\d+)
RewriteRule ^ /?%1 [L,R=301]

THE_REQUEST содержит полную строку запроса "GET /hot.html HTTP/1.1"

Кроме GET, POST, HEAD есть и другие методы.

https://ru.wikipedia.org/wiki/HTTP#.D0.9C.D0.B5.D1.82.D0.BE.D0.B4.D1.8B

RewriteEngine on

RewriteCond %{THE_REQUEST} ^[A-Z]{3,7}\ /index.php\?action=hot\ HTTP
RewriteRule ^ http://sait.ru/hot.html? [L,R=301]


RewriteRule ^hot\.html$ index.php?action=hot [L] 

или так

RewriteEngine on

RewriteCond %{ENV:REDIRECT_FINISH} =1
RewriteRule ^ - [L]

RewriteCond %{QUERY_STRING} ^action=hot$
RewriteRule ^index\.php$ http://sait.ru/hot.html? [L,R=301] 

RewriteRule ^hot\.html$ index.php?action=hot [L,E=FINISH:1] 

В .htaccess вставить сразу после RewriteEngine On

RewriteRule ^((\d{4})(\d\d)(\d\d)\d\d)\.html$ /$2/$3/$4/$1/ [R=301,L]

.htaccess в корне сайта

RewriteEngine On

RewriteCond %{QUERY_STRING} ^(cardid=\d+)&(sectionid=\d+)$
RewriteRule ^(selector/)$ /$1?%2&%1 [L,R=301]