Everyone would really like to have the exact receipt that they want. The problem is that everyone wants a receipt different from everyone else.
If you read the history of DHPOS here
http://www.dhpos.com/discuss/phpBB2/viewtopic.php?t=816 you will note the POS program that this one is based on. I actually met the person who wrote the program becasue he used my shop as one of the beta test sites.
While he is undoubtably a better programmer than I am he had it much easier than I do because he had only one client, my host department store. He only had to worry about one type of computer, one type of printer, one type of cash drawer, one type of tax (added), and one format for receipts. On the receipts there was only one length for stock numbers (6), one length for descriptions (10), one range for prices (0.00 to 999.99), and one rounding factor (.01). I wish my life was that easy.
DHPOS is designed to be used by almost everyone, almost everywhere, on almost any hardware. I have no idea how many digits their stock numbers will have (up to 14), what language their descriptions will use, what rounding factor they will use, the monetary range their prices will use (0.00 to 999999 and some folks want up to 999,999,999.99 for a price!), and I have no concept at all of how they must calculate their taxes.
Yet DHPOS must be able to accomodate what everyone needs. Just because you only need a 5 digit stock number there still has to be room for a 14 digit stock number because some stores require that. While no total price on one line (price times quantity) in your store may exceed 9999.99 some other store may require 9999999.99 so there must be room for that. I do not know what any individual user needs so I must make room for anything.
I think that I have come up with a receipt format that just about anyone can use that prints any and all required information.
So why not customizable receipts? The answer is time, code space, and comprehensability. Tell you what, I will give you 500 bytes to write the code for customizable receipts. It must be able to print any required information on the receipts, in any format, in any order, at both 40 and 80 characters per line. The 500 bytes are only to be able to actually print the receipts, you can use as much code as you need to allow the user to setup the format that they want. Make sure that your setup code is easy to understand and that you put in enough instructions so that users will be able to comprehend how to set up their receipts. Your code must be in QuickBASIC of course. I will also need a text file explaining how to setup a receipt format that I can add to the user's guide.
Sound like fun?