How do I find updates to the USB HID usage tables?

Specifically, I'm trying to find definitions for new digitizer page
report fields not found in the USB serial bus HID usage tables v. 1.12
(the latest on the USB web site).

The fields of interest have values of 0x47, 0x48, and 0x49, that are in
the reserved area of the digitizer's page in the 1.12 document.

			Thanks,
				- Jim Gettys

-- 
Jim Gettys [off-list ref]
One Laptop Per Child