RewriteEngine On

# Announcements
RewriteRule ^announcements/([0-9]+)/[a-z0-9_-]+\.html$ ./announcements.php?id=$1 [L,NC]
RewriteRule ^announcements$ ./announcements.php [L,NC]

# Downloads
RewriteRule ^downloads/([0-9]+)/([^/]*)$ ./downloads.php?action=displaycat&catid=$1 [L,NC]
RewriteRule ^downloads$ ./downloads.php [L,NC]

# Knowledgebase
RewriteRule ^knowledgebase/([0-9]+)/[a-z0-9_-]+\.html$ ./knowledgebase.php?action=displayarticle&id=$1 [L,NC]
RewriteRule ^knowledgebase/([0-9]+)/([^/]*)$ ./knowledgebase.php?action=displaycat&catid=$1 [L,NC]
RewriteRule ^knowledgebase$ ./knowledgebase.php [L,NC]