# Check that your Apache virtualhost have this settings:

#<Directory "/var/www/chamilo-classic">
#  AllowOverride All
#  Order allow,deny
#  Allow from all
#</Directory>



RewriteEngine on 
RewriteCond %{QUERY_STRING} ^id=(.*)$
RewriteRule ^certificates/$ certificates/index.php?id=%1 [L]
RewriteRule ^([^/.]+)/?$ user.php?$1 [L]

# This will transform
# http://my.chamilo.net/certificates/index.php?id=123 to http://my.chamilo.net/certificates/123
# http://my.chamilo.net/user.php?jmontoya  to http://my.chamilo.net/jmontoya