NV_pixel_data_range - Documentation ?

Scuse my ignorance, but I’ve done a search of these forums, and of the web.
I can find Spec’s for NV_pixel_data_range, but they only talk about what it does and don’t go into detail.
Can somebody direct me to a page detailing the API usage of NV_pixel_data_range ?

Also - is NV_pixel_data_range still in use or is it getting old now (with PBO’s and PCI-Express, say) ?

Regards
Jon

You can see in PBO specs and example of pixel_data_range, but it seems that it is replaced by the use of PBO.

http://www.opengl.org/registry/specs/EXT/pixel_buffer_object.txt

Thanks speed.

Jon