BEM (Block, Element, Modifier) is a naming convention for classes in HTML and CSS what was developed by Yandex.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
VK is a Russian online social media and social networking service.
YooMoney is an IT company working with electronic payments on the Internet, creating and supporting financial services for individuals and businesses.