CSS file versioning using htaccess file (Apache config)

.htaccess

# CSS file versioning using htaccess file (Apache config)
# Link to the file style.123456.css and the server will deliver style.css
# Change the number and the web browser will see it as a different file
# and force it to be loaded afresh
# permanenttourist.ch | mark@permanenttourist.ch | 6/2014 | Free use, no credit required

# Warning: use only numeric sequences for the version reference!
# Warning: if a file with the actual name really exists, it will be served!

RewriteCond %{REQUEST_FILENAME} !-s
RewriteRule ^(.*)\.[\d]+\.(css|js)$ $1.$2 [L]