anchor.diff:            the block it belongs to. Let's say that we have a menu item element and a button mixed together. In HTML this construction is represented
             by the following markup:
   
  -          ```
  +          ```html
             <div class="menu__item button"></div>
             ```
             In this case adding `.active` modifier to them would affect both.
   
  -          ```
  +          ```html
             <div class="menu__item button active"></div>
             ```
             All the 3 sit at the same DOM node, so it is impposible to differenciate if we mean `menu__item.active` or `button.active`.
  
positive.code:           Another point is CSS specifity. The combined selectors are more specific (means more important) than single class selectors.
            This means that you might have trouble when redefining them with parent block code.
  
            ```
            <div class="header">
              <button class="button active">
            </div>
  
negative.code:         :markdown
            We are working on Frequently Asked Question list [here](https://docs.google.com/document/d/1KD9tNdArCv1U1NvFX7rYPvUdbpPGVkuPZ2723KW5p4Y) — fear not, it will be translated from Russian to English before publishing.
  
            ### Why the modifier CSS classes are prefixed with their parent block name?
  
            > BEM recommends to modify blocks like this `<div class="block block_mod">`. Why not to use the simple version like `<div class="block mod">`? Since we now have combined selectors `.block.mod`, it's easy to define all the CSS properties to it.
  
  