code: function( data, tag, searchData ) {
  
  			var letter, l, depth = 2,
  				current = searchData;
  
  			for ( l = 0; l < depth; l++ ) {
  				letter = tag.substring(l, l + 1);
  				if (!current[letter] ) {
  					current[letter] = {};
  					current[letter].list = [];
  				}
  				if ( indexOf(current[letter].list, data) == -1 ) {
  					current[letter].list.push(data);
  				}
  				current = current[letter];
  			}
  		}
docs: goes through list and adds to search data