As traffic block a website with .htaccess?

Hello everyone I found this code .htaccess to block a website, but do not understand why in the first line is [NC, OR] and the second link does not? So okay if I want to block traffic 2 or more websites?

RewriteEngine on
# Options +FollowSymlinks
RewriteCond %{HTTP_REFERER} lsale02\.ru [NC,OR]
RewriteCond %{HTTP_REFERER} esoqld.ru\.ru  <------- **does not have [NC,OR]**
RewriteRule .* - [F]