Comment updated

Author: remedcu

contracts/standard/rng/BlockhashRNGFallbackRange.sol

@@ -30,7 +30,8 @@ contract BlockHashRNGFallback is BlockHashRNG {
      */
     function saveRN(uint _block) public {
         if (_block < block.number && randomNumber[_block] == 0) { // If the random number is not already set and can be.
-            // The below equation is valid for all cases (last 256 blockhash of blocks or even earlier than that).
+            // Returns the blockhash of _block if accessible (one of the last 256 blocks).
+            // If the blockhash hasn't been saved in time, return a blockhash of a block in range as a fallback.
             randomNumber[_block] = uint(blockhash((block.number-1) - (block.number-1-_block)%256));
         }