where are docs for VIRTUAL?

where are docs for VIRTUAL?

[Felix Miata]

I see VIRTUAL1 disconnected in Xorg.0.log, several bugs filed at 
freedesktop.org, an announcement of 2.99.901 at 
http://lists.freedesktop.org/archives/xorg/2013-September/055988.html and 
Google hits on cgit.freedesktop.org/xorg/driver/xf86-video-intel containing 
strings intel-virtual-output and/or intel-virtual-overlay, but after hours 
trying I don't seem to be able to spot any documentation about what *exactly* 
intel-virtual-output is or is supposed to be capable of. intel-virtual-output 
in 1.15.0 and 2.99.910 on openSUSE 13.2 produces command not found. 
Conspicuously absent from searching opensuse.org are both 
intel-virtual-output and VIRTUAL1.

1-where are the docs?

2-can it replace the missing release fix for 
https://bugs.freedesktop.org/show_bug.cgi?id=39949

3-if yes, is it supported on i865/i915/i945 hardware?
-- 
"The wise are known for their understanding, and pleasant
words are persuasive." Proverbs 16:21 (New Living Translation)

  Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!

Felix Miata  ***  http://fm.no-ip.com/