RewriteEngine on
RewriteBase /
RewriteRule ^contact?$ index.php?a=contact [L]
RewriteRule "^(.*)\s(.*)$" /$1+$2 [L,NE]
RewriteRule ^search/(.*)?$ index.php?a=search&search=$1 [L]
RewriteRule ^category/(.*)?$ index.php?a=category&category=$1 [L]
RewriteRule ^subject/(.*)?$ index.php?a=subject&subject=$1 [L]
RewriteRule ^play/(.*)?$ index.php?a=play&play=$1 [L]
RewriteRule ^embed/(.*)?$ index.php?a=embed&embed=$1 [L]
RewriteRule ^page/(.*)?$ index.php?a=page&prefix=$1 [L]