When someone is using a link on a forum or somewhere else using a trailing space, there can be a problem in the url returning a 404 error because the server sees a %20 at the end
for example ;
here is the .htaccess directive to correct that
RewriteCond %{THE_REQUEST} ^[A-Z]+\ /[^%?\ ]*\%
RewriteRule ^. / [R=301,L]