- The data for the inventory listings (complete,
last week, and
yesterday) is derived from a barcode scan - either the UPC code on the back cover, or (preferably) the EAN code on the inside front cover of paperbacks published since the mid-1980's. Really old books with no barcode (about 6% of my initial inventory) are not listed, as the required data entry would be too much work. The scanning is a manual process, not currently integrated with the actual sale or acceptance of books, so it's inevitable that there will be database errors due to missed or doubled scans.
- The actual identification I keep for each book is its ISBN (International Standard Book Number). This can be easily determined from the EAN barcode if present - indeed, under the new ISBN-13 system that goes into effect January 2007, the EAN code is the ISBN. For older books, it's usually possible to map the UPC code to an ISBN, but there's no guarantee of this (and any books for which this mapping fails will not appear in the online inventory).
- The ISBN is turned into a title, author's name, and other details by way of Amazon Web Services. Their database is impressively complete (less than 1% failed lookups so far), but not necessarily accurate as it was largely built from customer-submitted data. Errors I've seen range from inconsistently spelled author names, to titles that bear no resemblance at all to the actual book. I've submitted updates to Amazon for some of the most blatant errors, but I don't know how long it will take for the updates to be reviewed and added to the database.
- The cover images, which appear in some recent browsers if you point your mouse at a book title, are also supplied by Amazon. They may be from a different edition of the book than what I actually have in inventory.
- The inventory listings are alphabetized quite simplistically, using the last word of the first author's name. This doesn't always work: "L. Sprague de Camp" should properly be listed under "D", not "C", and "L.E. Modesitt, Jr." certainly doesn't belong in the "J"s! Proper alphabetization of names is extremely difficult, and the rules have changed over the years, so I'm probably not going to put much more effort into doing it right. It's not always appropriate, anyway: consider the six volumes of Isaac Asimov's Robot City. They clearly belong together, and in the store I have them shelved together in the "A"s. However, each of the six books was written by a different author, and they appear scattered throughout the online listing. If I had shelved them that way, nobody would be able to find them all! The moral of the story is: don't trust the ordering of books in the listings, use your browser's Find command if you know what you're looking for.
- The online listings are generated nightly, and do not reflect sales or trades made today.
- The listings for last month, last week, and yesterday do not currently include any books for which the most recent transaction was a sale - even if I still have another copy on hand that was acquired in the specified time period.
- Here are some more specialized inventory listings: books that I have more than one copy of, books that are in my database but that I don't currently have copies of.