This page is a work in progress...
This page describes how Accounting compresses and stores its data in the saved variables file. There are two main tables of information in the Accounting saved variables file: the "buy" and "sell" tables representing items which the player has purchased from the AH and sold on the AH repsectively.
Encoding the ItemString/ItemLink
If there the item link is available for the item, it'll look something like this: