docs: function brFilter( isOutput ) {
  			return function( br ) {
  				// DO NOT apply the filer if parent's a fragment node.
  				if ( br.parent.type == CKEDITOR.NODE_DOCUMENT_FRAGMENT )
  					return;
  
  				var attrs = br.attributes;
  				// Dismiss BRs that are either bogus or eol marker.
  				if ( 'data-cke-bogus' in attrs || 'data-cke-eol' in attrs ) {
  					delete attrs [ 'data-cke-bogus' ];
  					return;
  				}
  
  				// Judge the tail line-break BR, and to insert bogus after it.
  				var next = getNext( br ), previous = getPrevious( br );
  
  				if ( !next && isBlockBoundary( br.parent ) )
  					append( br.parent, createFiller( isOutput ) );
  				else if ( isBlockBoundary( next ) && previous && !isBlockBoundary( previous ) )
  					createFiller( isOutput ).insertBefore( next );
  			};
  		}