notes: commodids are offsets

diff --git a/yarrg/notes b/yarrg/notes
index 99438d96317f0e451db30b376248a41b6ef7986f..8895c7189430f6216e837c29c06803c3c473fbd0 100644 (file)
--- a/yarrg/notes
+++ b/yarrg/notes
@@ -73,11 +73,19 @@ format is a series of lines
  auxil <stallid>=:<stallname>
  auxil <metadataid>=&<metadatalenbytes>\n<metadata>
 
- log/old <metadataid>&<timestamp>              applies to following data
- log/old [<stallid>:]<commodid>                                        delete offer
- log/old [<stallid>:]<commodid>@<newprice>                     adjust price
- log/old [<stallid>:]<commodid>[@<newprice>]-<qtyreduced>      adjust qty
- log/old [<stallid>:]<commodid>[@<newprice>]+<qtyincreased>    maybe price
+ log/old <metadataid>&<timestamp>
+       applies to following data
+
+ log/old [<stallid>:]<commodiddelta>                            delete offer
+ log/old [<stallid>:]<commodiddelta>@<newprice>                         adjust price
+ log/old [<stallid>:]<commodiddelta>[@<newprice>]-<qtyreduced>  adjust qty
+ log/old [<stallid>:]<commodiddelta>[@<newprice>]+<qtyincreased>  maybe price
+       In each case commodiddelta is the number to add to
+       the previous commodid to get the new one; or for a new
+       stallid, the actual commodid (starting from zero).
+       -ve numbers cannot be represented so they have to be in
+       order.
+
  log    ^<uploadlenbytes-padded-to-4-base62-digits>
                        applies to previous data
                        includes 6-byte len of one ^... line