The description of the style:print-page-order in ODF 1.2 cd02 rev03 is:
The defined values for the style:print-page-order attribute are:
ltr: data is printed horizontally from the top row to the right column of a sheet.
ttb: data is printed vertically from the top row to the bottom column of a sheet.
In previous version we said:
Use ttb to print the data vertically from the left column to the bottom row of the sheet. Use ltr to print the data horizontally from the top row to the right column of the sheet.
Beside the fact that there is no "bottom column", the description changed from ODF 1.1. There is also a comment that the description was unclear in ODF 1.0 already:
Maybe we can find a description that resolves above issue and is also clearer than the one we had.