anchor.diff:                  You will not be surprised, that BEM is abbreviation of the key elements of the methodology — Block, Element and Modifier. Strict rules of naming can be found in [Naming](naming.html) article.
   
             .grid__row
  -            .grid__cell-lg_size_1
  -            .grid__cell-lg_size_3.grid__cell_left-border
  +            .grid__cell-lg_size_4.grid__cell_left-border
                 .heading.heading_level_1.heading_block Block
                 .raw-text
                   :markdown
  
positive.code:                   __Examples__
  
                    `header`, `container`, `menu`, `checkbox`, `input`
              .grid__cell-lg_size_3.grid__cell_left-border
                .heading.heading_level_1.heading_element Element
                .raw-text
                  :markdown
  
negative.code:                   __Examples__
  
                    `menu item`, `list item`, `checkbox caption`, `header title`
              .grid__cell-lg_size_4.grid__cell_left-border
                .heading.heading_level_1.heading_modifier Modifier
                .raw-text
                  :markdown
  