I had some url requests show up in my google sitemaps for one of my sites with "404 Not found" errors for a bunch of urls that had "%23comment-155" looking urls instead of "#comment-155"

The Urlencode RewriteRule Goal

/article.html%23comment-155

to

/article.html#comment-155

The Solution

RewriteRule ^(.*).html([^c]+)comment-(.+)$ http://www.site.com/$1.html#comment-$3 [R=301,L,NE]

Requests from apache log files

"GET /htaccess/speed-up-sites-with-htaccess-caching.html%23comment-155 HTTP/1.1" 200 2617 "-"

After the fix

"GET /htaccess/speed-up-sites-with-htaccess-caching.html%23comment-155 HTTP/1.1" 301 683 "-"
"GET /htaccess/speed-up-sites-with-htaccess-caching.html HTTP/1.1" 200 24690 "-"

Result

More Info