diff --git a/sql/bs.sql b/sql/bs.sql
index 4d526cc0..c39b6abe 100644
--- a/sql/bs.sql
+++ b/sql/bs.sql
@@ -1,3 +1,12 @@
+-- SQL to calculate a block's diffacc (difficulty accepted)
+-- This should match the block's confirmed diffacc
+--  i.e. when a block has statsconfirmed='Y'
+-- If the block has any unaged sharesummaries,
+--  the script will abort and report the count
+-- Sharesummaries are aged at ~10 minutes after the next workinfo,
+--  after the sharesummary's workinfo, was first generated
+-- You need to set the block number at line 21 - hi := blockheight;
+
 SET SESSION AUTHORIZATION 'postgres';
 
 DO $$
@@ -12,23 +21,30 @@ BEGIN
  hi := 318177;
 
  -- This will randomly choose between multiple blocks of the same height
- --  if we happen to orphan ourselves
+ --  if we happen to orphan ourselves on block 'hi'
  select workinfoid from blocks where height = hi
-	and expirydate > '6666-06-01' into wi;
+	and expirydate > '6666-06-01' limit 1 into wi;
  IF NOT found THEN
   RAISE EXCEPTION 'Block % not found', hi;
  END IF;
 
  select max(height) from blocks where height < hi into hi0;
- IF NOT found THEN
+ IF hi0 is NULL THEN
   wi0 := -1;
  ELSE
+  -- This will randomly choose between multiple blocks of the same height
+  --  if we happen to orphan ourselves on block 'hi0'
   select workinfoid from blocks where height = hi0
-	and expirydate > '6666-06-01' into Wi0;
+	and expirydate > '6666-06-01' limit 1 into wi0;
  END IF;
 
- RAISE WARNING 'Block: %(%)', hi, wi;
- RAISE WARNING 'Previous block: %(%)', hi0, wi0;
+ RAISE NOTICE 'Block: %(%)', hi, wi;
+
+ IF hi0 is NULL THEN
+  RAISE NOTICE 'No previous block';
+ ELSE
+  RAISE NOTICE 'Previous block: %(%)', hi0, wi0;
+ END IF;
 
  select count(*) from sharesummary where workinfoid > wi0
 	and workinfoid <= wi and complete = 'n' into ssc;
@@ -39,6 +55,6 @@ BEGIN
   select sum(diffacc) from sharesummary where workinfoid > wi0
 	and workinfoid <= wi into da;
 
-  RAISE WARNING 'diffacc: %', to_char(da::bigint, 'FM999,999,999,999,999,990');
+  RAISE NOTICE 'diffacc: %', to_char(da::bigint, 'FM999,999,999,999,999,990');
  END IF;
 END $$;